for Journals by Title or ISSN
for Articles by Keywords
help

Publisher: Elsevier   (Total: 3043 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

We no longer collect new content from this publisher because the publisher has forbidden systematic access to its RSS feeds.
Journal Cover European Journal of Medical Genetics
  [SJR: 0.934]   [H-I: 40]   [6 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1769-7212
   Published by Elsevier Homepage  [3043 journals]
  • Massively parallel sequencing on human cleavage-stage embryos to detect
           chromosomal abnormality
    • Abstract: Publication date: Available online 12 October 2017
      Source:European Journal of Medical Genetics
      Author(s): Zhi Zhou, Yanlin Ma, Qi Li, Yu Zhang, Yuanhua Huang, Zhihua Tu, Ning Ma, Minghong Li, Jun Wang, Jian Li, Weiying Lu
      Purpose Next-generation sequencing technology like MPS has recently been introduced to perform comprehensive chromosome screening on human trophectoderm samples for preimplantation embryo assessment. However, the potential of MPS in chromosome analysis of single cell from blastomeres has not yet been investigated. Methods In this study, 12 couples underwent MPS analysis, including 9 balanced translocation carriers and 3 carriers of numerical chromosomal abnormalities. Cleavage-stage (Day 3) embryos (n = 105) were biopsied with one cell removal. Single cell from blastomeres was processed by whole genome amplification (WGA). WGA products were subjected to both MPS and microarray-based comparative genomic hybridization (array-CGH). Euploid embryos identified as “balanced or normal” were selected for frozen-thawed embryo transfer (FET) cycles. Results Reliable MPS-PGD results as well as array CGH-PGD results were obtained for 101 biopsied cleavage-stage embryos. 18.8% (19/101) embryos were identified as “euploid and balanced” by both MPS and array-CGH. 20.8% (21/101) were unbalanced for the translocation but normal for aneuploidy.26.7% (27/101) had aneuploidy and were unbalanced. 33.7% (34/101) showed normal or balanced but still had aneuploidy of chromosomes. In identifications of embryo aneuploidy and imbalance, MPS and array-CGH showed 100% consistency, with the exception of 4 samples. After transferring 12 embryos with normal or balanced for every chromosome, 1 live birth and 5 ongoing clinical pregnancies were achieved. Conclusion In conclusion, as a flexible and cost-effective strategy and higher potential accuracy. MPS could be clinically applied to detect numeric abnormality of chromosome segments in day 3 preimplantation blastomeres.

      PubDate: 2017-10-14T05:44:20Z
       
  • Multiple SLC26A2 mutations occurring in a three-generational family
    • Abstract: Publication date: Available online 10 October 2017
      Source:European Journal of Medical Genetics
      Author(s): Ana Coral Barreda-Bonis, Jimena Barraza-García, Manuel Parrón, Ignacio Pastor, Karen E. Heath, Isabel González-Casado
      Multiple epiphyseal dysplasias (MED) are a group of heterogeneous skeletal dysplasias, which share a common phenotype: short stature, skeletal deformities, joint pain and early onset osteoarthritis. Mutations in COMP account for approximately half of autosomal dominant MED cases whilst SLC26A2 mutations account for ∼25% of the recessive cases in the Caucasian population. We present here an interesting family, which was thought to initially have an autosomal dominant skeletal dysplasia. Using a targeted sequencing skeletal dysplasia panel, the proband was found to be a compound heterozygote for two mutations in SLC26A2, one novel mutation, p.Ser522Phe and the other, the common mutation, p.Arg279Trp. In addition to the classical characteristics of MED, she presented with an atypical feature, bilateral synostoses between the 2nd and 3rd metatarsals. The parents were confirmed to be heterozygous for the two mutations but interestingly, the maternal grandfather, who had MED, was found to be homozygous for the common SLC26A2 mutation.

      PubDate: 2017-10-14T05:44:20Z
       
  • Left ventricular non-compaction with Ebstein anomaly attributed to a TPM1
           mutation
    • Abstract: Publication date: Available online 9 October 2017
      Source:European Journal of Medical Genetics
      Author(s): Aleksandra Nijak, Maaike Alaerts, Cuno Kuiperi, Anniek Corveleyn, Bert Suys, Bernard Paelinck, Johan Saenen, Emeline Van Craenenbroeck, Lut Van Laer, Bart Loeys, Aline Verstraeten
      Left ventricular non-compaction (cardiomyopathy) (LVN(C)) is a rare hereditary cardiac condition, resulting from abnormal embryonic myocardial development. While it mostly occurs as an isolated condition, association with other cardiovascular manifestations such as Ebstein anomaly (EA) has been reported. This congenital heart defect is characterized by downward displacement of the tricuspid valve and leads to diminished ventricular size and function. In an autosomal dominant LVN(C) family consisting of five affected individuals, of which two also presented with EA and two others with mitral valve insufficiency, we pursued the genetic disease cause using whole exome sequencing (WES). WES revealed a missense variant (p.Leu113Val) in TPM1 segregating with the LVN(C) phenotype. TPM1 encodes α-tropomyosin, which is involved in myocardial contraction, as well as in stabilization of non-muscle cytoskeletal actin filaments. So far, LVN(C)-EA has predominantly been linked to pathogenic variants in MYH7. However, one sporadic LVN(C)-EA case with a de novo TPM1 variant has recently been described. We here report the first LVN(C)-EA family segregating a pathogenic TPM1 variant, further establishing the association between EA predisposition and TPM1-related LVN(C). Consequently, we recommend genetic testing for both MYH7 and TPM1 in patients or families in which LVN(C)/non-compaction and EA coincide.

      PubDate: 2017-10-14T05:44:20Z
       
  • A classical Ehlers-Danlos syndrome family with incomplete presentation
           diagnosed by molecular testing
    • Abstract: Publication date: Available online 9 October 2017
      Source:European Journal of Medical Genetics
      Author(s): Marina Colombi, Chiara Dordoni, Valeria Cinquina, Marina Venturini, Marco Ritelli
      The 2017 EDS revised nosology indicates that minimal criteria suggestive for classical Ehlers-Danlos syndrome (cEDS) are skin hyperextensibility plus atrophic scarring together with either generalized joint hypermobility (gJHM) and/or at least three minor criteria that include cutaneous features and gJHM complications. Confirmatory molecular testing is obligatory to reach a final diagnosis. Although the large majority of the patients presents with these clinical features, some do not and might remain undiagnosed or misdiagnosed. Here we describe a family with 2 affected members, a 23-year-old proposita and her 51-year-old mother, who presented subtle cutaneous signs, including a variable degree of skin hyperextensibility without extensive widened atrophic scars that apparently better fitted with the overlapping hypermobile EDS. The proposita also presented gastrointestinal symptoms secondary to aberrant mast cells mediators release, making the clinical picture even more puzzling. Both patients were diagnosed by molecular testing that revealed a COL5A1 splice mutation. This report highlights the relevance of molecular analysis in patients presenting rather mild signs of EDS, especially in familial cases, and the importance of clinical expertise to make such a diagnosis.

      PubDate: 2017-10-14T05:44:20Z
       
  • Somatic second hit mutation of RASA1 in vascular endothelial cells in
           capillary malformation-arteriovenous malformation
    • Abstract: Publication date: Available online 9 October 2017
      Source:European Journal of Medical Genetics
      Author(s): Philip E. Lapinski, Abbas Doosti, Valerie Salato, Paula North, Patricia E. Burrows, Philip D. King
      Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal dominant vascular disorder that is associated with inherited inactivating mutations of the RASA1 gene in the majority of cases. Characteristically, patients exhibit one or more focal cutaneous CM that may occur alone or together with AVM, arteriovenous fistulas or lymphatic vessel abnormalities. The focal nature and varying presentation of lesions has led to the hypothesis that somatic “second hit” inactivating mutations of RASA1 are necessary for disease development. In this study, we examined CM from four different CM-AVM patients for the presence of somatically acquired RASA1 mutations. All four patients were shown to possess inactivating heterozygous germline RASA1 mutations. In one of the patients, a somatic inactivating RASA1 mutation (c.1534C > T, p.Arg512*) was additionally identified in CM lesion tissue. The somatic RASA1 mutation was detected within endothelial cells specifically and was in trans with the germline RASA1 mutation. Together with the germline RASA1 mutation (c.2125C > T, p.Arg709*) in the same patient, the endothelial cell somatic RASA1 mutation likely contributed to lesion development. These studies provide the first clear evidence of the second hit model of CM-AVM pathogenesis.

      PubDate: 2017-10-14T05:44:20Z
       
  • Distal renal tubular acidosis in a Libyan patient: Evidence for digenic
           inheritance
    • Abstract: Publication date: Available online 9 October 2017
      Source:European Journal of Medical Genetics
      Author(s): Majdi Nagara, Gregory Papagregoriou, Rim Ben Abdallah, Zied Landoulsi, Yosra Bouyacoub, Sahar Elouej, Rym Kefi, Tommaso Pippucci, Voskarides Konstantinos, Anu Bashamboo, Kenneth McElreavey, Mongia Hachicha, Giovanni Romeo, Marco Seri, Constantinos Deltas, Sonia Abdelhak
      Aim of the study Recent advances in understanding the underlying molecular mechanism for distal renal tubular acidosis (dRTA), led to an increased attention towards the primary and the familial forms of the disease. Mutations in ATP6V1B1 and ATP6V0A4 are usually responsible for the recessive form of the disease. Mutations in gene AE1 encoding the Cl-/HCO3- exchanger, usually present as dominant dRTA, but a recessive pattern has been recently described. Our objective is to identify the mutational spectrum responsible of dRTA in a consanguineous Libyan family. Materials and methods Both ATP6V0A4 and ATP6V1B1 genes were preferentially screened in our patient. Additional whole exome sequencing (WES) in the same patient, offered a wider view on potential chromosomal rearrangements as well as the mutational spectrum of other genes involved in this disease. Results The patient is a heterozygote for two different mutations, one in each of the genes ATP6V0A4 and ATP6V1B1, while no deleterious variation was detected in the remaining genes responsible for the recessive form of dRTA. Homozygosity mapping and WES confirmed our findings and supported the hypothesis of a digenic inheritance model existing as an explanation for dRTA. Conclusions To our knowledge, this is the first report describing a Libyan patient with dRTA who suffered from early-onset sensorineural hearing loss, with a digenic mode of inheritance, supported by the identification of two novel mutations. This study increases the understanding of how dRTA is genetically transmitted, while offers a good outline towards the molecular diagnostics and genetic counseling for dRTA in Lybians.

      PubDate: 2017-10-14T05:44:20Z
       
  • Letter regarding the article “Extending the phenotype of recurrent
           rearrangements of 16p11.2: Deletions in mentally retarded patients without
           autism and in normal individuals (Bijlsma et al., 2009)” and the
           diagnosis of coexisting Mowat-Wilson syndrome in a patient with 16p11.2
           deletion
    • Abstract: Publication date: Available online 9 October 2017
      Source:European Journal of Medical Genetics
      Author(s): David J. Amor, Emilia K. Bijlsma


      PubDate: 2017-10-14T05:44:20Z
       
  • The spectrum of Familial Mediterranean Fever gene (MEFV) mutations and
           genotypes in Iran, and report of a novel missense variant (R204H)
    • Abstract: Publication date: Available online 21 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Nader Ebadi, Abbas Shakoori, Masoumeh Razipour, Arash Salmaninejad, Razieh Zarifian Yeganeh, Saman Mehrabi, Seyed RezaRaees Karami, Malihea Khaleghian, Hamidreza Azhideh
      Background Familial Mediterranean Fever (FMF) is an autosomal recessive disorder, characterized by recurrent and self-limited episodes of fever, abdominal pain, synovitis and pleuritis. FMF as the most common inherited monogenic autoinflammatory disease mainly affects ethnic groups of the Mediterranean basin, Arab, Jewish, Turkish, Armenian North Africans and Arabic descent. Materials and methods In the present study, we selected 390 unrelated FMF patients according to the Tel-Hashomer criteria, and analyzed all patients for 12 most common mutations of MEFV gene by reverse hybridization assay (FMF strip assay). We also investigated exon 2 and 10 of MEFV gene in 78 patients by Sanger sequencing. Results According to strip assay results, at least one mutation was found in 234 patients (60%), and no mutation was found in other 156 patients (40%). The five most common mutations and allelic frequencies were M694V (13.6%), E148Q (10.4%), M694I (6.5%), V726A (4.1%), and M680I (3.8%). Moreover, we detected a novel missense variant (R204H, c.611 G > A) (SCV000297822) and following rare mutations among sequenced samples; R202Q, P115T, G304R, and E230K. Conclusion This study describes the MEFV mutations spectrum and distribution in Iranian population, and shows different mutation patterns among Iranian ethnicities. Moreover, M694V is the most common MEFV mutation in Iran.

      PubDate: 2017-09-24T00:25:15Z
       
  • A chinese boy with geleophysic dysplasia caused by compound heterozygous
           mutations in ADAMTSL2
    • Abstract: Publication date: Available online 14 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Li Dongxiao, Dong Hui, Zheng Hong, Song Jinqing, Li Xiyuan, Jin Ying, Liu Yupeng, Yang Yanling
      Geleophysic dysplasia, belonging to the group of acromelic dysplasia, is a rare genetic disease. Two genes, FBN1 and ADAMTSL2, were known to be linked to this disorder. The disorder presents as extreme short stature, short limbs, small hands and feet, stubby fingers and toes, joint stiffness, toe walking, skin thickening, progressive cardiac valvular thickening and characteristic facial features, including a round face with full cheeks. Here, we report the first Chinese case with geleophysic dysplasia type 1 based on clinical and genetic features. The boy was admitted because of severe physical growth retardation and mild motor retardation. Comprehensive medical evaluations were performed including metabolic studies, endocrine function examination, bone X-rays and echocardiography. Much delayed bone age and geleophysic dysplasia were found. Targeted next-generation sequencing was used to detect genetic mutations associated with skeletal dysplasia. Sanger sequencing was used to confirm the mutations in the patient. PCR amplification, cloing, and sequencing was used to determine the de novo mutation origin. Two compound heterozygous mutations were confirmed in the ADAMTSL2 gene of the patient. The c.340G > A (p.Glu114Lys) mutation was a de novo heterozygous mutation, and our results suggested that it was located on the paternal allele. While the c.234-2A > G inherited from his mother was a novel pathogenic heterozygous splicing mutation. Growth hormone deficiency had been observed in the patient. His growth velocity was improved by growth hormone supplementation. In conclusion, we have identified a novel splicing mutation of ADAMTSL2 carried by a Chinese boy with geleophysic dysplasia type 1. The patient was treated effectively with growth hormone supplementation.

      PubDate: 2017-09-18T00:08:51Z
       
  • Al-Awadi-Raas-Rothschild syndrome with dental anomalies and a novel WNT7A
           mutation
    • Abstract: Publication date: Available online 14 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Piranit Nik Kantaputra, Seema Kapoor, Prashant Verma, Massupa Kaewgahya, Katsushige Kawasaki, Atsushi Ohazama, James R. Ketudat Cairns
      Al-Awadi-Raas-Rothschild syndrome (AARRS; OMIM 276820) is a very rare autosomal recessive limb malformation syndrome caused by WNT7A mutations. AARRS is characterized by various degrees of limb aplasia and hypoplasia. Normal intelligence and malformations of urogenital system are frequent findings. Complete loss of WNT7A function has been shown to cause AARRS, however, its partial loss leads to the milder malformation, Fuhrmann syndrome. An Indian boy affected with AARRS is reported. A novel homozygous base substitution mutation c.550A > C (p.Asn184Asp) is identified in the patient. Parents were heterozygous for the mutation. In addition to the typical features of AARRS, the patient had agenesis of the mandibular left deciduous lateral incisor. The heterozygous parents had microdontia of the maxillary left permanent third molar and taurodontism (enlarged dental pulp chamber at the expense of root) in a number of their permanent molars. Whole exome sequencing of the patient and his parents ruled out mutations in 11 known hypodontia-associated genes including WNT10A, MSX1, EDA, EDAR, EDARADD, PAX9, AXIN2, GREM2, NEMO, KRT17, and TFAP2B. In situ hybridization during tooth development showed Wnt7a expression in wild-type tooth epithelium at E14.5. All lines of evidence suggest that WNT7A has important role in tooth development and its mutation may lead to tooth agenesis, microdontia, and taurodontism. Oral examination of patients with AARRS and Fuhrmann syndromes is highly recommended.

      PubDate: 2017-09-18T00:08:51Z
       
  • Genetics of clubfoot; recent progress and future perspectives
    • Abstract: Publication date: Available online 14 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Sulman Basit, Khalid I. Khoshhal
      Clubfoot or talipes equinovarus (TEV) is an inborn three-dimensional deformity of leg, ankle and foot. It results from structural defects of several tissues of foot and lower leg leading to abnormal positioning of foot and ankle joints. TEV can lead to long-lasting functional disability, malformation and discomfort if left untreated. Substantial progress has been achieved in the management and diagnosis of limb defects; however, not much is known about the molecular players and signalling pathways underlying TEV disorder. The homeostasis and development of the limb depends on the complex interactions between the lateral plate mesoderm cells and outer ectoderm. These complex interactions include HOX signalling and PITX1-TBX4 pathways. The susceptibility to develop TEV is determined by a number of environmental and genetic factors, although the nature and level of interplay between them remains unclear. Familial occurrence and inter and intra phenotypic variability of TEV is well documented. Variants in genes that code for contractile proteins of skeletal myofibers might play a role in the aetiology of TEV but, to date, no strong candidate genes conferring increased risk have emerged, although variants in TBX4, PITX1, HOXA, HOXC and HOXD clusters genes, NAT2 and others have been shown to be associated with TEV. The mechanisms by which variants in these genes confer risk and the nature of the physical and genetic interaction between them remains to be determined. Elucidation of genetic players and cellular pathways underlying TEV will certainly increase our understanding of the pathophysiology of this deformity.

      PubDate: 2017-09-18T00:08:51Z
       
  • A homozygote TREX1 mutation in two siblings with different phenotypes:
           Chilblains and cerebral vasculitis
    • Abstract: Publication date: Available online 13 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Rabia Miray Kisla Ekinci, Sibel Balci, Atil Bisgin, Derya Ufuk Altintas, Mustafa Yılmaz
      Three prime repair exonuclease 1 degrades single and double stranded DNA with 3′-5′ nuclease activity and its mutations are related to type 1 IFN mediated autoinflammation due to accumulated intracellular nucleic acids. To date, several cases of systemic lupus erythematosus, Aicardi-Goutieres syndrome, familial chilblain lupus, retinal vasculopathy-cerebral leukodystrophy have been reported with TREX1 mutations. Chilblain lupus is a skin disease characterized by blue-reddish coloring, swelling or ulcers on acral regions of body such as fingertips, heels, nose and auricles. Central nervous system vasculitis is a prominent cause of childhood strokes. 10 families with familial chilblain lupus related to TREX1 mutations were reported previously in the literature, in which homozygote D18N variant in TREX1 gene was related to chilblains with cerebral vasculitis. In this report, whole-exome-sequencing revealed a homozygote R114C mutation in TREX1 gene was shown in two siblings with recurrent chilblains whom one of them was the second case accompanied by cerebral vasculitis in the literature. As a result, the approach of WES in clinical use revealed a novel mutation in clinically heterogenous patients to provide genetic counseling.

      PubDate: 2017-09-18T00:08:51Z
       
  • Exome sequencing for the differential diagnosis of ciliary
           chondrodysplasias: Example of a WDR35 mutation case and review of the
           literature
    • Abstract: Publication date: Available online 12 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Dinu Antony, Narayanan Nampoory, Chiara Bacchelli, Motasem Melhem, Kaman Wu, Chela T. James, Philip L. Beales, Mike Hubank, Daisy Thomas, Anant Mashankar, Kazem Behbehani, Miriam Schmidts, Osama Alsmadi
      Exome sequencing is becoming widely popular and affordable, making it one of the most desirable methods for the identification of rare genetic variants for clinical diagnosis. Here, we report the clinical application of whole exome sequencing for the ultimate diagnosis of a ciliary chondrodysplasia case presented with an initial clinical diagnosis of Asphyxiating Thoracic Dystrophy (ATD, Jeune Syndrome). We have identified a novel homozygous missense mutation in WDR35 (c.206G > A), a gene previously associated with Sensenbrenner Syndrome, Ellis-van Creveld syndrome and Short-rib polydactyly syndrome type V. The genetic findings in this family led to the re-evaluation of the initial diagnosis and a differential diagnosis of Sensenbrenner Syndrome was made after cautious re-examination of the patient. Cell culture studies revealed normal subcellular localization of the mutant WDR35 protein in comparison to wildtype protein, pointing towards impaired protein-protein interaction and/or altered cell signaling pathways as a consequence of the mutated allele. This research study highlights the importance of including pathogenic variant identification in the diagnosis pipeline of ciliary chondrodysplasias, especially for clinically not fully defined phenotypes.

      PubDate: 2017-09-18T00:08:51Z
       
  • Case report: Left ventricular noncompaction cardiomyopathy and RASopathies
    • Abstract: Publication date: Available online 12 September 2017
      Source:European Journal of Medical Genetics
      Author(s): John Lynn Jefferies, Carlos Enrique Prada, Juli Ann Sublett
      The following is a case report of 6 patients with Noonan syndrome (NS) and/or a related RASsopathy that also have evidence of left ventricular noncompaction cardiomyopathy (LVNC). Noonan syndrome,a type of RASopathy, is an autosomal dominant disorder that is typically associated with congenital heart defects and hypertrophic cardiomyopathy. There have been minimal reports of Noonan syndrome or other RASopathy and the association of LVNC. This report promulgates 6 nonrelated cases of Noonan syndrome or unspecified RASopathy and LVNC.

      PubDate: 2017-09-18T00:08:51Z
       
  • Familial 9q33q34 microduplication in siblings with developmental disorders
           and acrocephaly
    • Abstract: Publication date: Available online 9 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Keiko Shimojima, Nobuhiko Okamoto, Himanshu Goel, Yumiko Ondo, Toshiyuki Yamamoto
      Because several genes responsible for epileptic encephalopathy are located on the 9q33q34 region, patients with chromosomal deletions of this region often show intractable epilepsy and neurodevelopmental disability. Contrary to these findings, chromosomal duplications of this region have never been reported previously. We identified a first case of 9q33q34 microduplications in siblings associated with developmental disorders and macrocephaly. Their mother was a mosaic carrier of this duplication. Duplicated regions involved STXBP1; the gene related to epileptic encephalopathy. Neurological features including developmental delay and macrocephaly observed in the present siblings may be derived from the extra-copy of STXBP1.

      PubDate: 2017-09-11T23:35:07Z
       
  • High bone mass due to novel LRP5 and AMER1 mutations
    • Abstract: Publication date: Available online 8 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Alice Costantini, Päivi Kekalainen, Riikka E. Mäkitie, Outi Mäkitie
      WNT signaling is a key regulator of bone metabolism and its increased or decreased activity leads to skeletal disorders. Here we describe two patients with high bone mass (HBM) caused by novel mutations in two different WNT pathway components. The first patient is a 53-year-old male with HBM. He was diagnosed at adult age based on significantly increased bone mineral density (BMD). He has undergone several surgeries due to excessive bone in ear canals, bilateral jaw exostoses and mandibular tori. Radiographs show severe cortical thickening of cranial and long bones. Sanger sequencing identified a novel heterozygous mutation c.592A > T (p.N198Y) in LRP5 (Low-density lipoprotein receptor-related protein 5). The second patient, an adolescent female, was diagnosed with skeletal dysplasia in early childhood. She had macrocephaly (head circumference +6.0 SD), facial dysmorphism, delayed motor development, laryngomalasia, and epilepsy. Radiographic findings were consistent with osteopathia striata with cranial sclerosis. A novel heterozygous frameshift mutation c.655del (p.E219Rfs*63) in AMER1 (APC Membrane Recruiting Protein 1) was identified. Although both mutations are predicted to lead to increased WNT signaling with a consequent increase in bone formation, the resulting phenotypes are different; cranial sclerosis versus macrocephaly, long bone cortical thickening versus vertical striations, and discordant neurological development. This report underscores the diversity of genotypes and phenotypes of HBM and facilitates their differential diagnosis.

      PubDate: 2017-09-11T23:35:07Z
       
  • Efficient detection of chromosome imbalances and exome single nucleotide
           variants using targeted sequencing in the clinical setting
    • Abstract: Publication date: Available online 4 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Darine Villela, Silvia Souza da Costa, Angela M. Vianna-Morgante, Ana C.V. Krepischi, Carla Rosenberg
      We evaluated an approach to detect copy number variants (CNVs) and single nucleotide changes (SNVs), using a clinically focused exome panel complemented with a backbone and SNP probes that allows for genome-wide copy number changes and copy-neutral absence of heterozygosity (AOH) calls; this approach potentially substitutes the use of chromosomal microarray testing and sequencing into a single test. A panel of 16 DNA samples with known alterations ranging from megabase-scale CNVs to single base modifications were used as positive controls for sequencing data analysis. The DNA panel included CNVs (n = 13) of variable sizes (23 Kb to 27 Mb), uniparental disomy (UPD; n = 1), and single point mutations (n = 2). All DNA sequence changes were identified by the current platform, showing that CNVs of at least 23 Kb can be properly detected. The estimated size of genomic imbalances detected by microarrays and next generation sequencing are virtually the same, indicating that the resolution and sensitivity of this approach are at least similar to those provided by DNA microarrays. Accordingly, our data show that the combination of a sequencing platform comprising focused exome and whole genome backbone, with appropriate algorithms, enables a cost-effective and efficient solution for the simultaneous detection of CNVs and SNVs.

      PubDate: 2017-09-05T23:07:46Z
       
  • Gait disturbance and lower limb pain in a patient with PIK3CA-related
           disorder
    • Abstract: Publication date: Available online 1 September 2017
      Source:European Journal of Medical Genetics
      Author(s): Gerarda Cappuccio, Marianna Alagia, Mariangela D'Anna, Carlotta Ranieri, Silvia Di Tommaso, Claudio Bruno, Chiara Fiorillo, Marina Pedemonte, Daria Loconte, Roberto Della Casa, Pietro Strisciuglio, Maria Isabella Ginocchio, Michele Pinelli, Nicoletta Resta, Nicola Brunetti-Pierri
      Post-zygotic activating mutations in PIK3CA and other genes encoding members of PI3K-AKT-mTOR pathway have been found in various overgrowth syndromes that have been grouped together as PIK3CA-related overgrowth spectrum (PROS). We report a female patient with gait disturbance, leg pain, isolated macrodactyly of the foot, and mild intellectual disability. Imaging of the lower limb showed a lipoblastoma of the right thigh. A mosaic gain-of-function mutation in the catalytic domain of PIK3CA (c.3140 A > G; p.His1047Arg) was detected in the adipose tissue and in skin cultured fibroblasts from the macrodactyly but not in blood. The leg pain and the severe walking disturbance improved slightly over time and serial MRI of the lower limbs suggested that the size of the lipoblastoma relative to the lower limb muscles or to the whole lower limb slightly decreased as consequence of limb growth. This case report illustrates that pain and gait disturbance can be features of PROS and highlights the need of better knowledge about the natural history of the disease.

      PubDate: 2017-09-05T23:07:46Z
       
  • Very early onset inflammatory bowel disease: Investigation of the IL-10
           signaling pathway in Iranian children
    • Abstract: Publication date: Available online 30 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Shahram Nemati, Shahram Teimourian, Mina Tabrizi, Mehri Najafi, Naghi Dara, Farid Imanzadeh, Mitra Ahmadi, Maryam Kazemi Aghdam, Mohmoud Tavassoli, Pejman Rohani, Seyyed Ramin Madani, Martin de Boer, T.W. Kuijpers, Dirk Roos
      Background & aim Comparing to adult inflammatory bowel disease (IBD), those with early onset manifestations have different features in terms of the underlying molecular pathology, the course of disease and the response to therapy. We investigated the IL-10 signaling pathway previously reported as an important cause of infantile (Very Early Onset) IBD to find any possible variants. Method With the next generation sequencing technique we screened IL-10, IL-10RA and IL10RB genes of 15 children affected by very early onset-GI (gastrointestinal) disorders. Additionally, we analyzed them based on Thermo Fisher immune deficiency panel for genes either having a known role in IBD pathogenesis or cause the disorders with overlapping manifestations. We performed multiple functional analyses only for the cases showing variants in IL-10- related genes. Result In 3 out of 15 patients we identified variants including a homozygous and heterozygote mutations in IL-10RA and a novel homozygous mutation in IL-12RB1. Our functional studies reveal that in contrast to the IL-10RA heterozygote mutation that does not have deleterious effects, the homozygous mutation abrogates the IL-10 signaling pathway. Conclusion Our study suggests we need to modify the classical diagnostic approach from functional assays followed by candidate- gene or genes sequencing to the firstly parallel genomic screening followed by functional studies.

      PubDate: 2017-09-05T23:07:46Z
       
  • Mutations in DDHD1, encoding a phospholipase A1, is a novel cause of
           retinopathy and neurodegeneration with brain iron accumulation
    • Abstract: Publication date: Available online 14 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Rodolphe Dard, Claire Meyniel, Valérie Touitou, Giovanni Stevanin, Foudil Lamari, Alexandra Durr, Claire Ewenczyk, Fanny Mochel
      Defects of phospholipids remodelling and synthesis are inborn errors of metabolism responsible for various clinical presentations including spastic paraplegia, retinopathy, optic atrophy, myo- and cardiomyopathies, and osteo-cutaneous manifestations. DDHD1 encodes a phospholipase A1, which is involved in the remodelling of phospholipids. We previously described a relatively pure hereditary spastic paraplegia (HSP) phenotype associated with mutations in DDHD1. Here we report a complex form of HSP associated with retinal dystrophy and a pattern of neurodegeneration with brain iron accumulation (NBIA) on brain MRI, due to a novel homozygous mutation in DDHD1. This observation enlarges the clinical spectrum of DDHD1-associated disorders and sheds light on a new aetiology for syndromes associating retinopathy and NBIA. It also emphasizes the role of complex lipids in the retina.

      PubDate: 2017-08-26T20:07:13Z
       
  • Human imprinting disorders: Principles, practice, problems and progress
    • Abstract: Publication date: Available online 14 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Deborah J.G. Mackay
      Epigenetic regulation orchestrates gene expression with exquisite precision, over a huge dynamic range and across developmental space and time, permitting genomically-homogeneous humans to develop and adapt to their surroundings. Every generation, these epigenetic marks are re-set twice: in the germline, to enable differentiation of sperm and eggs, and at fertilisation, to create the totipotent zygote that then begins growth and differentiation into a new human. A small group of genes evades the second, zygotic wave of epigenetic reprogramming, and these genes retain an epigenetic ‘imprint’ of the parent from whom they were inherited. Imprinted genes are (as a general rule) expressed from one parental allele only. Some imprinted genes are critical regulators of growth and development, and thus disruption of their normal monoallelic expression causes congenital imprinting disorders, with clinical features impacting growth, development, behaviour and metabolism. Imprinting disorders as a group have characteristics that challenge diagnosis and management, including clinical and molecular heterogeneity, overlapping clinical features, somatic mosaicism, and multi-locus involvement. New insights into the biology and epigenomics of the early embryo offers new clues about the origin and importance of imprinting disorders.

      PubDate: 2017-08-26T20:07:13Z
       
  • A structured assessment of motor function, behavior, and communication in
           patients with Wolf–Hirschhorn syndrome
    • Abstract: Publication date: Available online 14 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Heidi E. Nag, David K. Bergsaker, Bente S. Hunn, Susanne Schmidt, Lise B. Hoxmark
      The present study aimed to increase the knowledge about Wolf–Hirschhorn syndrome (WHS), especially concerning motor function, autism spectrum disorders (ASD), and adapted behavior, but also regarding clinical symptoms in general. Motor function was evaluated via systematic observation. Standardized assessments such as the Vineland Adapted Behavior Scales II (VABS II), the Social Communication Questionnaire (SCQ), and the Child Behavior Checklist (CBCL) or Adult Behavior Checklist (ABCL) were used for the behavioral assessment. In total, two males and eight females between one and 48 years of age with a genetically confirmed diagnosis of WHS and their parents participated in this study. Deletion sizes were known for seven of the ten patients and varied between 55 Kb and 20 Mb. The chromosome coordinates were known for six of them, and none of those had the same break points in their deletion. The main finding in this study was that patients with WHS may have a better outcome regarding motor skills and expressive communication than previously described. We could confirm the main medical findings described earlier, but found also a population with a less severe dysmorphology, fewer congenital malformations, and fewer medical challenges than expected. Sleep problems may persist into adulthood and need a more thorough investigation. Research on possible indications of ASD is strongly needed for targeted interventions. In conclusion, a more thorough assessment of communication, possible ASD, and sleep in larger groups of patients with WHS are needed to confirm and further investigate the findings from this study and to provide more targeted interventions for WHS patients.

      PubDate: 2017-08-26T20:07:13Z
       
  • Early fetal presentation of Koolen-de Vries: Case report with literature
           review
    • Abstract: Publication date: Available online 12 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Fanny Sauvestre, Florent Marguet, Caroline Rooryck, Marie-Laure Vuillaume, Frédéric Cardinaud, Annie Laquerrière, Gwenaëlle André, Fanny Pelluard
      Koolen-de Vries syndrome (MIM#610443) is a rare microdeletion syndrome involving the 17q21.31 region, which was first described by Koolen in 2006. Clinical and behavioral characteristics have been extensively reported from more than 100 postnatal cases including infants, children and young adults. The syndrome is highly clinically heterogeneous, but the main features associate characteristic cranio-facial dysmorphism, heart defects, limb, skeletal, genito-urinary anomalies, along with intellectual disability with early childhood epilepsy and behavioral disturbances. Central nervous system malformations usually consist in hydrocephalus and thin corpus callosum. We report herein an early fetal case with an apparently isolated abnormal corpus callosum diagnosed by ultrasonography, for which a medical termination of the pregnancy was achieved at 22 weeks of gestation. Postmortem examination displayed facial dysmorphism consisting of hypertelorism, short philtrum and flat and broad nose, cleft palate and left duplex ureter. Neuropathological examination revealed a mega corpus callosum that has never been reported so far in this syndrome. Array-CGH performed on thymic DNA tissue revealed a 17q21.31 microdeletion, which allowed for the confirmation of early occurring Koolen-de Vries syndrome.

      PubDate: 2017-08-26T20:07:13Z
       
  • Familial 1p36.3 microduplication resulting from a 1p-9q non-reciprocal
           translocation
    • Abstract: Publication date: Available online 12 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Valentine Marquet, Sylvie Bourthoumieu, Amelia Dobrescu, Cécile Laroche-Raynaud, Catherine Yardin
      Unlike the 1p36 microdeletion syndrome, which has been extensively described, 1p36 microduplications have rarely been reported. We describe a three years old boy presenting with a severe global developmental delay and a few dysmorphic features. Cytogenetic analyses revealed a maternally inherited 3.35 Mb microduplication of chromosomal band 1p36.3. The maternal grand-father is also carrier of the same chromosomal rearrangement. Interestingly, the duplicated 1p36.3 segment was found to be localized at the telomeric end of the long arms of a chromosome 9, probably deriving from a 1p36.3-9qter non-reciprocal translocation. This particular type of chromosomal translocation has rarely been reported, and its mechanism is unclear. The phenotypical features associated with 1p36.3 microduplication vary due to the non-recurrent breakpoints of the rearrangements in this particular region. However, when compiling the few described cases, the phenotypical spectrum seems to include mainly developmental delay, mild facial dysmorphism, and neurological, cardiac and skeletal anomalies. The description of new patients carrying a 1p36.3 duplication like ours will lead to further delineation of the phenotypical spectrum and may help to find critical regions and causative genes implicated in the phenotype.

      PubDate: 2017-08-26T20:07:13Z
       
  • Diagnostic exome sequencing identifies a heterozygous MBD5 frameshift
           mutation in a family with intellectual disability and epilepsy
    • Abstract: Publication date: Available online 12 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Ji Yoon Han, In Goo Lee, Woori Jang, Myungshin Kim, Yonggoo Kim, Ja Hyun Jang, Joonhong Park
      Methyl-CpG-binding domain 5 (MBD5)-associated neurodevelopmental disorder caused by 2q23.1 or MBD5-specific mutation has been recently identified as a genetic disorder associated with autism spectrum disorders. Phenotypic features of 2q23.1 deletion or disruption of MBD5 gene include severe intellectual disability, seizure, significant speech impairment, sleep disturbance, and autistic-like behavioural problems. Here we report a 7-year-old girl with intellectual disability and epilepsy without previous clinical diagnosis. Diagnostic exome sequencing identified a novel frameshift mutation c.254_255delGA (p.Arg85Asnfs*6) in the MBD5 gene of the proband and her father. The proband's father with normal intelligence showed subclinical manifestations observed in subsequent investigations. Clinical manifestations, disease course, and molecular findings of the involvement of MBD5 gene in this family suggest an unusual MBD5-related neurodevelopmental disorder. Moreover, this report demonstrates the critical role of next-generation sequencing technique in characterizing such a rare disorder with variable or no clinical manifestation and providing opportunity to develop effective preventive measures such as pre-implantation genetic diagnosis.

      PubDate: 2017-08-26T20:07:13Z
       
  • BRCA1/2 missense mutations and the value of in-silico analyses
    • Abstract: Publication date: Available online 12 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Carolin E. Sadowski, Daniela Kohlstedt, Cornelia Meisel, Katja Keller, Kerstin Becker, Luisa Mackenroth, Andreas Rump, Evelin Schröck, Pauline Wimberger, Karin Kast
      Introduction The clinical implications of genetic variants in BRCA1/2 in healthy and affected individuals are considerable. Variant interpretation, however, is especially challenging for missense variants. The majority of them are classified as variants of unknown clinical significance (VUS). Computational (in-silico) predictive programs are easy to access, but represent only one tool out of a wide range of complemental approaches to classify VUS. With this single-center study, we aimed to evaluate the impact of in-silico analyses in a spectrum of different BRCA1/2 missense variants. Methods We conducted mutation analysis of BRCA1/2 in 523 index patients with suspected hereditary breast and ovarian cancer (HBOC). Classification of the genetic variants was performed according to the German Consortium (GC)-HBOC database. Additionally, all missense variants were classified by the following three in-silico prediction tools: SIFT, Mutation Taster (MT2) and PolyPhen2 (PPH2). Results Overall 201 different variants, 68 of which constituted missense variants were ranked as pathogenic, neutral, or unknown. The classification of missense variants by in-silico tools resulted in a higher amount of pathogenic mutations (25% vs. 13.2%) compared to the GC-HBOC-classification. Altogether, more than fifty percent (38/68, 55.9%) of missense variants were ranked differently. Sensitivity of in-silico-tools for mutation prediction was 88.9% (PPH2), 100% (SIFT) and 100% (MT2). Conclusion We found a relevant discrepancy in variant classification by using in-silico prediction tools, resulting in potential overestimation and/or underestimation of cancer risk. More reliable, notably gene-specific, prediction tools and functional tests are needed to improve clinical counseling.

      PubDate: 2017-08-15T17:24:44Z
       
  • Impairment of different protein domains causes variable clinical
           presentation within Pitt-Hopkins syndrome and suggests intragenic
           molecular syndromology of TCF4
    • Abstract: Publication date: Available online 12 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Maria Francesca Bedeschi, Giuseppe Marangi, Maria Rosaria Calvello, Stefania Ricciardi, Francesca Pia Chiara Leone, Marco Baccarin, Silvana Guerneri, Daniela Orteschi, Marina Murdolo, Serena Lattante, Silvia Frangella, Beth Keena, Margaret H. Harr, Elaine Zackai, Marcella Zollino
      Pitt-Hopkins syndrome is a neurodevelopmental disorder characterized by severe intellectual disability and a distinctive facial gestalt. It is caused by haploinsufficiency of the TCF4 gene. The TCF4 protein has different functional domains, with the NLS (nuclear localization signal) domain coded by exons 7–8 and the bHLH (basic Helix-Loop-Helix) domain coded by exon 18. Several alternatively spliced TCF4 variants have been described, allowing for translation of variable protein isoforms. Typical PTHS patients have impairment of at least the bHLH domain. To which extent impairment of the remaining domains contributes to the final phenotype is not clear. There is recent evidence that certain loss-of-function variants disrupting TCF4 are associated with mild ID, but not with typical PTHS. We describe a frameshift-causing partial gene deletion encompassing exons 4–6 of TCF4 in an adult patient with mild ID and nonspecific facial dysmorphisms but without the typical features of PTHS, and a c.520C > T nonsense variant within exon 8 in a child presenting with a severe phenotype largely mimicking PTHS, but lacking the typical facial dysmorphism. Investigation on mRNA, along with literature review, led us to suggest a preliminary phenotypic map of loss-of-function variants affecting TCF4. An intragenic phenotypic map of loss-of-function variants in TCF4 is suggested here for the first time: variants within exons 1–4 and exons 4–6 give rise to a recurrent phenotype with mild ID not in the spectrum of Pitt-Hopkins syndrome (biallelic preservation of both the NLS and bHLH domains); variants within exons 7–8 cause a severe phenotype resembling PTHS but in absence of the typical facial dysmorphism (impairment limited to the NLS domain); variants within exons 9–19 cause typical Pitt-Hopkins syndrome (impairment of at least the bHLH domain). Understanding the TCF4 molecular syndromology can allow for proper nosology in the current era of whole genomic investigations.

      PubDate: 2017-08-15T17:24:44Z
       
  • Reducing diagnostic turnaround times of exome sequencing for families
           requiring timely diagnoses
    • Abstract: Publication date: Available online 12 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Aurélie Bourchany, Christel Thauvin-Robinet, Daphné Lehalle, Ange-Line Bruel, Alice Masurel-Paulet, Nolwenn Jean, Sophie Nambot, Marjorie Willems, Laetitia Lambert, Salima El Chehadeh-Djebbar, Elise Schaefer, Aurélia Jaquette, Judith St-Onge, Charlotte Poe, Thibaud Jouan, Martin Chevarin, Patrick Callier, Anne-Laure Mosca-Boidron, Nicole Laurent, Mathilde Lefebvre, Frédéric Huet, Nada Houcinat, Sébastien Moutton, Christophe Philippe, Frédéric Tran-Mau-Them, Antonio Vitobello, Paul Kuentz, Yannis Duffourd, Jean-Baptiste Rivière, Julien Thevenon, Laurence Faivre
      Background and objective Whole-exome sequencing (WES) has now entered medical practice with powerful applications in the diagnosis of rare Mendelian disorders. Although the usefulness and cost-effectiveness of WES have been widely demonstrated, it is essential to reduce the diagnostic turnaround time to make WES a first-line procedure. Since 2011, the automation of laboratory procedures and advances in sequencing chemistry have made it possible to carry out diagnostic whole genome sequencing from the blood sample to molecular diagnosis of suspected genetic disorders within 50 h. Taking advantage of these advances, the main objective of the study was to improve turnaround times for sequencing results. Methods WES was proposed to 29 patients with severe undiagnosed disorders with developmental abnormalities and faced with medical situations requiring rapid diagnosis. Each family gave consent. The extracted DNA was sequenced on a NextSeq500 (Illumina) instrument. Data were analyzed following standard procedures. Variants were interpreted using in-house software. Each rare variant affecting protein sequences with clinical relevance was tested for familial segregation. Results The diagnostic rate was 45% (13/29), with a mean turnaround time of 40 days from reception of the specimen to delivery of results to the referring physician. Besides permitting genetic counseling, the rapid diagnosis for positive families led to two pre-natal diagnoses and two inclusions in clinical trials. Conclusions This pilot study demonstrated the feasibility of rapid diagnostic WES in our primary genetics center. It reduced the diagnostic odyssey and helped provide support to families.

      PubDate: 2017-08-15T17:24:44Z
       
  • A novel mutation in SMOC1 and variable phenotypic expression in two
           patients with Waardenburg anophthalmia syndrome
    • Abstract: Publication date: Available online 12 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Javad Jamshidi, Shokoufeh Abdollahi, Hamid Ghaedi, Elham Alehabib, Abbas Tafakhori, Somayeh Alinaghi, Marjan Chapi, Amir Hossein Johari, Hossein Darvish
      Waardenburg anophthalmia syndrome (WAS) is a rare disorder that mostly affects the eyes and distal limbs. In the current study we reported two Iranian patients with WAS. The first case was a 26-year-old girl with unilateral anophthalmia, bilateral camptodactyly and clinodactyly in her hands, oligodactly in her left foot and syndactyly of the second to fifth toes in her right foot. She also had severe hearing loss in both ears. The second case was a 12-year-old boy with bilateral anophthalmia, camptodactyly in his right hand, oligodactyly in his foot, clubfoot, and cryptorchidism. Both patients were mentally normal. To detect the causative mutation all exons and exon-intron boundaries of SMOC1 gene were sequenced in patients and other normal family members. We found a homozygous missense mutation (NM_001034852.2(SMOC1):c.367T > C) in exon 3 of SMOC1 gene in both patients. As the mutation segregated with the disease in the family, it should be the causative mutation. Our study extended the mutation spectrum of SMOC1 gene related to WAS.

      PubDate: 2017-08-15T17:24:44Z
       
  • Prenatal diagnosis of complex phenotype in a 13-week-old fetus with an
           
    • Abstract: Publication date: Available online 12 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Feodora Stipoljev, Danka Miric-Tesanic, Tomislav Hafner, Maja Barbalic, Monika Logara, Ruzica Lasan-Trcic, Ana Vicic, Romana Gjergja-Juraski
      We report the first trimester three-dimensional ultrasonographic findings in a 13-week-old fetus with complex phenotype and a de novo 4.7 Mb multigene deletion encompassing chromosome region 20q13.13-q13.2 detected by chromosomal microarray. Fetal sonography detected radial-ray anomalies in the form of bilateral absence of thumbs and the left club hand deformity. The presence of single atrioventricular canal instead of the atrial septal defect typical for Holt-Oram syndrome pointed us to rather suspect the SALL4 related diseases. Central nervous system anomaly in the form of enlarged lateral brain ventricles with choroid plexus shifted backwards was not previously reported as a part of SALL4 related disorders. The pregnancy was terminated at 14 + 3 weeks of pregnancy and the autopsy confirmed ultrasonographic findings. Deleted region included 38 genes, where only SALL4, ADNP and KCNB1 heterozygote pathogenic variants were described to because of syndromic forms. Radial ray anomalies are common part of clinical picture of SALL4 related disorders. Despite the lack of prenatally described cases, we hypothesized that maldevelopment of lateral brain ventriculomegaly could be very early sonographic sign of disturbed ADNP expression causing Helsmoortel-Van der Aa syndrome, but in some extent also of KCNB1 related early-onset epileptic encephalopathy. Furthermore, the possible dosage-dependent influence of recessive genes located in this region cannot be also excluded. The use of genome-wide technologies enables the detection of subtle chromosomal imbalances and more precise familial genetic counseling regarding actual and future pregnancies.

      PubDate: 2017-08-15T17:24:44Z
       
  • A de novo mosaic mutation in SPAST with two novel alternative alleles and
           chromosomal copy number variant in a boy with spastic paraplegia and
           autism spectrum disorder
    • Abstract: Publication date: Available online 1 August 2017
      Source:European Journal of Medical Genetics
      Author(s): A.M. Matthews, M. Tarailo-Graovac, E.M. Price, I. Blydt-Hansen, A. Ghani, B.I. Drögemöller, W.P. Robinson, C.J. Ross, W.W. Wasserman, H. Siden, C.D. van Karnebeek
      Here we report a 12 year old male with an extreme presentation of spastic paraplegia along with autism and dysmorphisms. Whole exome sequencing identified a predicted pathogenic pair of missense variants in SPAST at the same chromosomal location, each with a different alternative allele, while a chromosome microarray identified a 1.73 Mb paternally inherited copy gain of 1q21.1q21.2 resulting in a blended phenotype of both Spastic paraplegia 4 and 1q21.1 microduplication syndrome. We believe that the extreme phenotype observed is likely caused by the presence of cells which contain only mutant SPAST, but that the viability of the patient is possible due mosaicism of mutant alleles observed in different proportions across tissues.

      PubDate: 2017-08-05T15:40:12Z
       
  • Reporting practices for variants of uncertain significance from next
           generation sequencing technologies
    • Abstract: Publication date: Available online 1 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Danya F. Vears, Karine Sénécal, Pascal Borry
      The nature of next generation sequencing technologies (NGS) results in the generation of large amounts of data and the identification of numerous variants, for some of which the clinical significance may be difficult to ascertain based on our current knowledge. These Variants of Uncertain Significance (VUS) may be identified in genes in which the function is known or unknown and which may or may not be related to the original rationale for sequencing the patient. Little is known about whether laboratories report VUS to clinicians and current guidelines issued by some of the most notable professional bodies do not provide specific recommendations on this point. To address this, 26 interviews were conducted with 27 laboratory personnel, representing 24 laboratories in Europe (12), Canada (5) and Australasia (7) in order to explore their reporting practices. Participants highlighted that the classification of variants is a real challenge despite the presence of classification guidelines. We identified variation in the reporting practices of VUS across the laboratories within the study. While some laboratories limit their reporting to variants that are pathogenic and thought to be causative of the phenotype, more commonly laboratories report VUS when they are identified in genes related to the clinical question. Some laboratories will also report VUS in candidate genes. VUS that are secondary findings are generally not reported. While it is unclear whether uniformity in reporting is desirable, exploring the perspectives of laboratory personnel undertaking these analyses are critical to ensure the feasibility of any future reporting recommendations.

      PubDate: 2017-08-05T15:40:12Z
       
  • Exome sequence identified a c.320A > G ALG13 variant in a female with
           infantile epileptic encephalopathy with normal glycosylation and random X
           inactivation: Review of the literature
    • Abstract: Publication date: Available online 1 August 2017
      Source:European Journal of Medical Genetics
      Author(s): Sana Hamici, Fatma Bastaki, Mohamed Khalifa
      Congenital Disorders of Glycosylation (CDG) are new and rapidly expanding neurometabolic disorders with multisystem involvements, broad phenotypic manifestations, and variable severity. The majority results from a defect of one of the steps involved with protein or lipid N-glycosylation pathway. Almost all are inherited in autosomal recessive patterns with a few exceptions such as the X-linked ALG13. Mutations of ALG13 are reported, so far in only 10 patients, all were ascertained through exome/genome sequencing. Specifically, the ALG13 c.320A > G (p.Asn107Ser) variant was reported only in females and in all were de novo mutations. These findings may suggest an X-linked dominant inheritance of this mutation with embryonic male lethality. These patients presented with severe infantile epileptic encephalopathy, global developmental delay, and multisystem abnormalities. Only two of these females had glycosylation studies done, and both showed normal pattern of glycosylated serum transferrin isoforms, and none had their X-chromosome inactivation patterns studied. Here, we report on another female patient who is heterozygous for the same ALG13 c.320A > G (p.Asn107Ser) variant. She presented with infantile spasms, epileptic encephalopathy, hypsarrhythmia, hypotonia, developmental delay, intellectual disability, abnormal coagulation profile, feeding problems, hypotonia, and dysmorphic features. The diagnosis of CGD was suspected clinically, but glycosylation studies were done twice and showed normal patterns on both occasions. Her X-inactivation study was also done and, surprisingly, showed a random pattern of X-inactivation, with no evidence of skewness.

      PubDate: 2017-08-05T15:40:12Z
       
  • Ehlers Danlos syndrome, kyphoscoliotic type due to Lysyl Hydroxylase 1
           deficiency in two children without congenital or early onset
           kyphoscoliosis
    • Abstract: Publication date: Available online 27 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Fleur S. van Dijk, Grazia M.S. Mancini, Alessandra Maugeri, Jan M. Cobben
      We report two children with Ehlers Danlos, kyphoscoliotic type confirmed by Lysyl Hydroxylase 1 deficiency due to bi-allelic PLOD1 mutations (kEDS-PLOD1) who were initially thought to have either a diagnosis of classical EDS (cEDS) or a neuromuscular disorder due to absence of (congenital) scoliosis. As the two patients reported here illustrate, patients with kEDS-PLOD1 do not always have a kyphoscoliosis present at birth or in the first year of life, neither do they necessarily develop kyphoscoliosis later in infancy. Using the past criteria for kEDS there was considerable overlap with the clinical diagnostic criteria for EDS classical type. In the patients reported here without (kypho) scoliosis this has delayed the diagnosis, which is unfortunate as the diagnosis of kEDS-PLOD1 results in a different recurrence risk and has management consequences. Interestingly, the new criteria for kEDS would not have prevented this diagnostic delay as congenital or early onset kyphoscoliosis (progressive or non-progressive) is deemed obligatory for the diagnosis of kEDS. Being aware of the limitations of clinical diagnostic criteria, we recommend that (i) in patients without a positive family history nor identified COL5A1/2 mutations, lysyl hydroxylase deficiency or biallelic PLOD1 mutations should be excluded before the diagnosis classical EDS can be made and (ii) PLOD1 and COL5A1/2 should be included in the same Next Generation Sequencing (NGS) gene panel.

      PubDate: 2017-08-05T15:40:12Z
       
  • Confirmation that mutations in DDX59 cause an autosomal recessive form of
           oral-facial-digital syndrome: Further delineation of the DDX59 phenotype
           in two new families
    • Abstract: Publication date: Available online 12 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Sara Faily, Rahat Perveen, Jill Urquhart, Kate Chandler, Jill Clayton-Smith
      We report three probands from two unrelated consanguineous families of South Asian origin who all carry the same rare novel homozygous variant within the dead box helicase gene DDX59 in association with features of oral-facial-digital syndrome (OFDS). DDX59 variants have been reported previously in an unclassified, autosomal recessive form of OFDS; clinically associated with features including tongue lobulation, cleft palate, frontal bossing, hypertelorism and postaxial polydactyly. All three probands had lobulated tongues with tongue hamartomas, abnormal tongue tip, developmental delay and microcephaly, with just one proband demonstrating polydactlyly. The novel DDX59 variant was identified through autozygosity studies followed by sequencing of homozygous regions identified. It affects a stop codon, extending the protein product and is therefore predicted to be pathogenic. It is only the third reported DDX59 mutation associated with OFDS reported so far.

      PubDate: 2017-07-21T11:22:27Z
       
  • Homozygous c.359del variant in MGME1 is associated with early onset
           cerebellar ataxia
    • Abstract: Publication date: Available online 12 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Malavika Hebbar, Katta M. Girisha, Anshika Srivastava, Stephanie Bielas, Anju Shukla
      We ascertained a child with early onset cerebellar ataxia and identified a novel frameshift deletion, c.359del [p. (Pro120Leufs*2), NM_052865.2] in exon 2 of MGME1 (mitochondrial genome maintenance exonuclease 1) by exome sequencing. Variations in MGME1 have been reported to cause mitochondrial DNA (mtDNA) depletion syndrome 11 (MIM #615084) in an earlier work. The phenotype included progressive external ophthalmoplegia, emaciation, respiratory failure and late onset progressive ataxia. However, the child presented here has early onset progressive ataxia, speech delay, microcephaly, cerebellar atrophy and fundus albipunctatus. This is the second report of a mutation in MGME1 and describes a more severe phenotype.

      PubDate: 2017-07-21T11:22:27Z
       
  • Microcephaly with simplified gyral pattern, epilepsy and permanent
           neonatal diabetes syndrome (MEDS). A new patient and review of the
           literature
    • Abstract: Publication date: Available online 12 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Irene Valenzuela, Susana Boronat, Elena Martínez-Sáez, María Clemente, Ángel Sánchez-Montañez, Francina Munell, Antonio Carrascosa, Alfons Macaya
      Microcephaly with simplified gyration, epilepsy and permanent neonatal diabetes syndrome (MEDS) is a recently described, autosomal recessive-inherited syndrome. We report the case of an infant presenting with lethargy at age five weeks and clinical findings of persistent hyperglycaemia and microcephaly with simplified gyration, suggestive of MEDS. The diagnosis was confirmed by the detection of a known c.233 T > C mutation in the IER3IP1 gene. Only eight cases of MEDS have been reported in the literature. We reviewed these with the aim of better delineating their clinical manifestations, which should allow earlier and more accurate diagnosis and genetic counseling.

      PubDate: 2017-07-21T11:22:27Z
       
  • Early manifestations of epileptic encephalopathy, brain atrophy, and
           elevation of serum neuron specific enolase in a boy with beta-propeller
           protein-associated neurodegeneration
    • Abstract: Publication date: Available online 12 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Kyoko Takano, Kazuya Goto, Mitsuo Motobayashi, Keiko Wakui, Rie Kawamura, Tomomi Yamaguchi, Yoshimitsu Fukushima, Tomoki Kosho
      Mutations in WDR45 are responsible for beta-propeller protein-associated neurodegeneration (BPAN), which is an X-linked form of neurodegeneration with brain iron accumulation. BPAN mainly affects females and is characterized by seizures and developmental delay or intellectual disability until adolescence or early adulthood, followed by severe dystonia, parkinsonism, and progressive dementia. However, rare male patients have recently been reported with hemizygous germline mutations in WDR45 and severe clinical manifestations, such as epileptic encephalopathies. We report here a 4-year-old boy presenting with profound developmental delay, non-syndromic epileptic encephalopathy, and early brain atrophy. The level of serum neuron specific enolase (NSE) was elevated, but the level of serum phosphorylated neurofilament heavy chain was not detectable. Targeted next-generation sequencing identified a de novo hemizygous splice donor site mutation, c.830+1G > A in WDR45, which resulted in a splicing defect evidenced by reverse transcriptase-PCR. Mutations in WDR45 should be considered as a cause for epileptic encephalopathies in males with profound developmental delay and brain atrophy. Furthermore, elevation of serum NSE may contribute to early diagnosis of BPAN.

      PubDate: 2017-07-21T11:22:27Z
       
  • SMD Kozlowski type caused by p.Arg594His substitution in TRPV4 reveals
           abnormal ossification and notochordal remnants in discs and vertebrae
    • Abstract: Publication date: Available online 4 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Tadeusz Bieganski, Peter Beighton, Maciej Lukaszewski, Krzysztof Bik, Lukasz Kuszel, Ewa Wasilewska, Kazimierz Kozlowski, Malwina Czarny-Ratajczak
      Spondylometaphyseal dysplasia Kozlowski type (SMDK) is a monogenic disorder within the TRPV4 dysplasia spectrum and has characteristic spinal and metaphyseal involvement. We report skeletal MR imaging in a two-year-old patient who manifested typical clinical and radiographic features of SMDK. The diagnosis was confirmed by molecular analysis which revealed a mutation NM_021625.4:c.1781G > A - p.(Arg594His) in exon 11 of the TRPV4 gene. We have documented abnormalities in endochondral formation of the long and short tubular bones as well as round bones of the wrists and feet. The vertebral bodies had increased thickness of hyaline cartilage which enveloped ossification centers. The vertebrae and discs also had abnormalities in size, shape and structure. These anomalies were most likely the consequence of notochordal remnants presence within the intervertebral discs and in the vertebral bodies. The advantages of MR imaging in bone dysplasias caused by TRPV4 mutations are emphasized in this article.

      PubDate: 2017-07-10T09:50:04Z
       
  • First de novo ANK3 nonsense mutation in a boy with intellectual
           disability, speech impairment and autistic features
    • Abstract: Publication date: Available online 4 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Katja Kloth, Jonas Denecke, Maja Hempel, Jessika Johannsen, Tim M. Strom, Christian Kubisch, Davor Lessel
      Ankyrin-G, encoded by ANK3, plays an important role in neurodevelopment and neuronal function. There are multiple isoforms of Ankyrin-G resulting in differential tissue expression and function. Heterozygous missense mutations in ANK3 have been associated with autism spectrum disorder. Further, in three siblings a homozygous frameshift mutation affecting only the longest isoform and a patient with a balanced translocation disrupting all isoforms were documented. The latter four patients were affected by a variable degree of intellectual disability, attention deficit hyperactivity disorder and autism. Here, we report on a boy with speech impairment, intellectual disability, autistic features, macrocephaly, macrosomia, chronic hunger and an altered sleeping pattern. By trio-whole-exome sequencing, we identified the first de novo nonsense mutation affecting all ANK3 transcripts. Thus, our data expand the phenotype of ANK3-associated diseases and suggest an isoform-based, phenotypic continuum between dominant and recessive ANK3-associated pathologies.

      PubDate: 2017-07-10T09:50:04Z
       
  • The first patient with sporadic X-linked intellectual disability with de
           novo ZDHHC9 mutation identified by targeted next-generation sequencing
    • Abstract: Publication date: Available online 4 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Ji Yoon Han, In Goo Lee, Soyoung Shin, Myungshin Kim, Ja Hyun Jang, Joonhong Park
      X-linked intellectual disability (XLID) is a genetically heterogeneous disorder involving more than 100 genes known to date. Here, we describe a Korean male infant with global developmental delay. He had neither facial dysmorphism nor skeletal abnormalities. Bayley scale of infant and toddler development third edition (Bayley-III) measured at age of 2 years revealed marked global developmental delays without Marfanoid habitus, structural brain abnormalities, or epilepsy. The patient's cognitive, motor, and language developmental ages were 8–9 months, 12 months, and 9 months, respectively. Targeted next-generation sequencing revealed a de novo mutation [NM_001008222.2(ZDHHC9): c.286C > T (p.(Arg96Trp))] in the affected patient. This mutation has been reported previously in a family XLID with Marfanoid features. Sanger sequencing analysis of the proband and his parents revealed that the missense mutation was present in the proband only (absent in his parents). This indicates that the mutation is de novo in origin. To the best of our knowledge, this is the first report describing sporadic XLID with de novo ZDHHC9 mutation identified by targeted next-generation sequencing.

      PubDate: 2017-07-10T09:50:04Z
       
  • Pierpont syndrome associated with the p.Tyr446Cys missense mutation in
           TBL1XR1
    • Abstract: Publication date: Available online 4 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Anne Slavotinek, Heather Pua, Ugur Hodoglugil, Jude Abadie, Joseph Shieh, Jessica Van Ziffle, Mark Kvale, Hane Lee, Pui-Yan Kwok, Neil Risch, Marta Sabbadini
      We present a 7-year old male with severe delays, hypotonia and dysmorphic features who had striking, deep palmar and plantar creases and pillowing of the soft tissues of the palms and soles. His facial features included a high anterior hairline, small eyes with narrowed palpebral fissures, a bulbous nasal tip with a short columella, and a large mouth with a thin upper vermilion, and small chin. He had a submucous cleft palate, bilateral cryptorchidism and hydronephrosis. Cranial imaging demonstrated an Arnold Chiari malformation that was also present in his maternal uncle by report. Exome sequencing revealed a de novo heterozygous sequence variant, p.Tyr446Cys, in TBL1XR1 that has previously been reported in six patients with Pierpont syndrome. This sequence variant occurs in the carboxy-terminal, WD40 domain of the protein. As TBL1XR1 is a critical component of the NCoR/SMRT co-repressor complex and the WD40 repeats are hypothesized to interact with histone H2B and H4, the mutation may impact protein interactions necessary for stabilizing the complex with chromatin. De novo missense and frameshift mutations and deletions involving TBL1XR1 have been described in patients with intellectual disability and autism, but without any of the dysmorphic findings or malformations associated with Pierpont syndrome, implying a mutation-specific mechanism for the pathogenicity of p.Tyr446Cys. Our case is the first individual with this mutation to have a submucous cleft palate and hydronephrosis, although his severe delays, hypotonia, dysmorphic findings and emerging scoliosis appear consistent with previous reports. His distinctive facial and digital features are further evidence that p.Tyr446Cys results in a clinically recognizable, syndromic form of intellectual disability in contrast to other TBL1XR1 mutations.

      PubDate: 2017-07-10T09:50:04Z
       
  • Testicular Adrenal Rest Tumor (TART) in congenital adrenal hyperplasia
    • Abstract: Publication date: Available online 1 July 2017
      Source:European Journal of Medical Genetics
      Author(s): Hatice Ozisik, Banu Sarer Yurekli, Ilgin Yildirim Simsir, Ilker Altun, Utku Soyaltın, Ezgi Guler, Huseyin Onay, Banu Sarsik, Fusun Saygili
      Congenital adrenal hyperplasia is one of the most common autosomal recessive genetic disorders. Testicular adrenal tumors are significant complications of congenital adrenal hyperplasia. We would like to present two patients of testicular adrenal rest tumors. Patient 1 24 year-old male, he was diagnosed with congenital adrenal hyperplasia at the age of 8 due to precocious puberty. He received hydro-cortisone treatment until the age of 18. Testicular mass had been detected and right radical orchiectomy had been applied 6 months ago and reported as testicular adrenal rest tumor. In scrotal ultrasound, a mixed type mass lesion (6 × 4x3 cm) covering a large part of left testis was observed. The imaging findings were consistent with adrenal rest tumor. The patient took adrenocorticotropic hormone supressive therapy with dexamethasone 0.75 mg once a day. Patient 2, 38 year-old male, he had been followed-up as adrenal insufficiency for 35 years. He underwent right orchiectomy operation due to the testicular mass in 2010 and the pathological examination revealed Leydig cell tumor. In scrotal ultrasound, small multifocal lesions were detected on the left testis and resection was done. It was reported as testicular adrenal rest tumor. He is being followed-up with glucocorticoid treatment according to androgen and adrenocorticotropic hormone levels. Early diagnosis of testicular adrenal rest tumor is significant in preventing irreversible testicular damage and infertility. In the differential diagnosis, we should keep in mind that testicular adrenal rest tumor can mimic other testicular tumors such as primary germ cell tumors.

      PubDate: 2017-07-01T07:18:11Z
       
  • Genotype-phenotype evaluation of MED13L defects in the light of a novel
           truncating and a recurrent missense mutation
    • Abstract: Publication date: Available online 21 June 2017
      Source:European Journal of Medical Genetics
      Author(s): Reza Asadollahi, Markus Zweier, Laura Gogoll, Raphael Schiffmann, Heinrich Sticht, Katharina Steindl, Anita Rauch
      A decade after the designation of MED13L as a gene and its link to intellectual disability (ID) and dextro-looped transposition of great arteries in 2003, we previously described a recognizable syndrome due to MED13L haploinsufficiency. Subsequent reports of 22 further patients diagnosed by genome-wide testing further delineated the syndrome with expansion of the phenotypic spectrum and showed reduced penetrance for congenital heart defects. We now report two novel patients identified by whole exome sequencing, one with a de novo MED13L truncating mutation and the other with a de novo missense mutation. The first patient indicates some facial resemblance to Kleefstra syndrome as a novel differential diagnosis, and the second patient shows, for the first time, recurrence of a MED13L missense mutation (p.(Asp860Gly)). Notably, our in silico modelling predicted this missense mutation to decrease the stability of an alpha-helix and thereby affecting the MED13L secondary structure, while the majority of published missense mutations remain variants of uncertain significance. Review of the reported patients with MED13L haploinsufficiency indicates moderate to severe ID and facial anomalies in all patients, as well as severe speech delay and muscular hypotonia in the majority. Further common signs include abnormal MRI findings of myelination defects and abnormal corpus callosum, ataxia and coordination problems, autistic features, seizures/abnormal EEG, or congenital heart defects, present in about 20–50% of the patients. With reference to facial anomalies, the majority of patients were reported to show broad/prominent forehead, low set ears, bitemporal narrowing, upslanting palpebral fissures, depressed/flat nasal bridge, bulbous nose, and abnormal chin, but macroglossia and horizontal eyebrows were also observed in ∼30%. The latter are especially important in the differential diagnosis of 1p36 deletion and Kleefstra syndromes, while the more common facial gestalt shows some resemblance to 22q11.2 deletion syndrome. Despite the fact that MED13L was found to be one of the most common ID genes in the Deciphering Developmental Disorders Study, further detailed patient descriptions are needed to explore the full clinical spectrum, potential genotype-phenotype correlations, as well as the role of missense mutations and potential mutational hotspots along the gene.

      PubDate: 2017-06-22T04:02:17Z
       
  • High-throughput sequencing of the entire genomic regions of CCM1/KRIT1,
           CCM2 and CCM3/PDCD10 to search for pathogenic deep-intronic splice
           mutations in cerebral cavernous malformations
    • Abstract: Publication date: Available online 20 June 2017
      Source:European Journal of Medical Genetics
      Author(s): Matthias Rath, Sönke E. Jenssen, Konrad Schwefel, Stefanie Spiegler, Dana Kleimeier, Christian Sperling, Lars Kaderali, Ute Felbor
      Cerebral cavernous malformations (CCM) are vascular lesions of the central nervous system that can cause headaches, seizures and hemorrhagic stroke. Disease-associated mutations have been identified in three genes: CCM1/KRIT1, CCM2 and CCM3/PDCD10. The precise proportion of deep-intronic variants in these genes and their clinical relevance is yet unknown. Here, a long-range PCR (LR-PCR) approach for target enrichment of the entire genomic regions of the three genes was combined with next generation sequencing (NGS) to screen for coding and non-coding variants. NGS detected all six CCM1/KRIT1, two CCM2 and four CCM3/PDCD10 mutations that had previously been identified by Sanger sequencing. Two of the pathogenic variants presented here are novel. Additionally, 20 stringently selected CCM index cases that had remained mutation-negative after conventional sequencing and exclusion of copy number variations were screened for deep-intronic mutations. The combination of bioinformatics filtering and transcript analyses did not reveal any deep-intronic splice mutations in these cases. Our results demonstrate that target enrichment by LR-PCR combined with NGS can be used for a comprehensive analysis of the entire genomic regions of the CCM genes in a research context. However, its clinical utility is limited as deep-intronic splice mutations in CCM1/KRIT1, CCM2 and CCM3/PDCD10 seem to be rather rare.

      PubDate: 2017-06-22T04:02:17Z
       
  • NGS panel analysis in 24 ectopia lentis patients; a clinically relevant
           test with a high diagnostic yield
    • Abstract: Publication date: Available online 19 June 2017
      Source:European Journal of Medical Genetics
      Author(s): E. Overwater, K. Floor, D. van Beek, K. de Boer, T. van Dijk, Y. Hilhorst-Hofstee, A.J.M. Hoogeboom, K.J. van Kaam, J.M. van de Kamp, M. Kempers, I.P.C. Krapels, H.Y. Kroes, B. Loeys, S. Salemink, C.T.R.M. Stumpel, V.J.M. Verhoeven, E. Wijnands-van den Berg, J.M. Cobben, J.P. van Tintelen, M.M. Weiss, A.C. Houweling, A. Maugeri
      Background Several genetic causes of ectopia lentis (EL), with or without systemic features, are known. The differentiation between syndromic and isolated EL is crucial for further treatment, surveillance and counseling of patients and their relatives. Next generation sequencing (NGS) is a powerful tool enabling the simultaneous, highly-sensitive analysis of multiple target genes. Objective The aim of this study was to evaluate the diagnostic yield of our NGS panel in EL patients. Furthermore, we provide an overview of currently described mutations in ADAMTSL4, the main gene involved in isolated EL. Methods A NGS gene panel was analysed in 24 patients with EL. Results A genetic diagnosis was confirmed in 16 patients (67%). Of these, four (25%) had a heterozygous FBN1 mutation, 12 (75%) were homozygous or compound heterozygous for ADAMTSL4 mutations. The known European ADAMTSL4 founder mutation c.767_786del was most frequently detected. Conclusion The diagnostic yield of our NGS panel was high. Causative mutations were exclusively identified in ADAMTSL4 and FBN1. With this approach the risk of misdiagnosis or delayed diagnosis can be reduced. The value and clinical implications of establishing a genetic diagnosis in patients with EL is corroborated by the description of two patients with an unexpected underlying genetic condition.

      PubDate: 2017-06-22T04:02:17Z
       
  • Digenic inheritance of mutations in the cardiac troponin (TNNT2) and
           cardiac beta myosin heavy chain (MYH7) as the cause of severe dilated
           cardiomyopathy
    • Abstract: Publication date: Available online 19 June 2017
      Source:European Journal of Medical Genetics
      Author(s): Evmorfia Petropoulou, Mohammadhossein Soltani, Ali Dehghani Firoozabadi, Seyedeh Mahdieh Namayandeh, Jade Crockford, Reza Maroofian, Yalda Jamshidi
      Familial dilated cardiomyopathy (DCM) is characterized by ventricular dilation and depressed myocardial performance. It is a genetically heterogeneous disorder associated with mutations in over 60 genes. We carried out whole exome sequencing in combination with cardiomyopathy-related gene-filtering on two affected family members to identify the possible causative mutation in a consanguineous Iranian family with DCM. Two novel variants in cardiomyopathy-related genes were identified: c.247 A > C; p.N83H in the Troponin T Type 2 gene (TNNT2) and c.2863G > A; p.D955N in the Myosin Heavy Polypeptide 7 gene (MYH7). Sanger sequencing and co-segregation analysis in the remaining family members supported the coexistence of these digenic mutations in affected members of the family. Carriers of either variant alone were asymptomatic. In summary, we find that digenic inheritance of two novel variants in DCM related genes is associated with a severe form of DCM. Exome sequencing has been shown to be very useful in identifying pathogenic mutations in cardiomyopathy families, and this report emphasizes the importance of comprehensive screening of DCM related genes, even after the identification of a single disease-causing mutation.

      PubDate: 2017-06-22T04:02:17Z
       
  • A novel missense variant (Gln220Arg) of GNB4 encoding guanine
           nucleotide-binding protein, subunit beta-4 in a Japanese family with
           autosomal dominant motor and sensory neuropathy
    • Abstract: Publication date: Available online 19 June 2017
      Source:European Journal of Medical Genetics
      Author(s): Shiroh Miura, Takuya Morikawa, Ryuta Fujioka, Kazuhito Noda, Kengo Kosaka, Takayuki Taniwaki, Hiroki Shibata
      Dominant intermediate Charcot–Marie–Tooth disease F (CMTDIF) is an autosomal dominant hereditary form of Charcot–Marie–Tooth disease (CMT) caused by variations in the guanine nucleotide-binding protein, subunit beta-4 gene (GNB4). We examined two Japanese familial cases with CMT. Case 1 was a 49-year-old male whose chief complaint was slowly progressive gait disturbance and limb dysesthesia that appeared at the age of 47. On neurological examination, he showed hyporeflexia or areflexia, distal limb muscle weakness, and distal sensory impairment with lower dominancy. Nerve conduction studies demonstrated demyelinating sensorimotor neuropathy with reduced action potentials in the lower limbs. Case 2 was an 80-year-old man, Case 1's father, who reported difficulty in riding a bicycle at the age of 76. On neurological examination, he showed areflexia in the upper and lower limbs. Distal sensory impairment in the lower limbs was also observed. Nerve conduction studies revealed mainly axonal involvement. Exome sequencing identified a novel heterozygous nonsynonymous variant (NM_021629.3:c.659T > C [p.Gln220Arg]) in GNB4 exon 8, which is known to be responsible for CMT. Sanger sequencing confirmed that both patients are heterozygous for the variation, which causes an amino acid substitution, Gln220Arg, in the highly conserved region of the WD40 domain of GNB4. The frequency of this variant in the Exome Aggregation Consortium Database was 0.000008247, and we confirmed its absence in 502 Japanese control subjects. We conclude that this novel GNB4 variant is causative for CMTDIF in these patients, who represent the first record of the disease in the Japanese population.

      PubDate: 2017-06-22T04:02:17Z
       
  • Postzygotic telomere capture causes segmental UPD, duplication and
           deletion of chromosome 8p in a patient with intellectual disability and
           obesity
    • Abstract: Publication date: Available online 8 June 2017
      Source:European Journal of Medical Genetics
      Author(s): Jeroen Knijnenburg, Madiek E.W. Uytdewilligen, Daniella A.C.M. van Hassel, Rianne Oostenbrink, Bert H.J. Eussen, Annelies de Klein, Alice S. Brooks, Laura J.C.M. van Zutven
      Using SNP array and FISH analysis, a patient with moderate intellectual disability and obesity was found to harbour an atypical 1.6 Mb inverted duplication on 8p23.1, directly flanked by a distally located interstitial deletion of 2.3 Mb and a terminal segmental uniparental disomy. The duplicated and deleted regions lie exactly between the two segmental duplication regions. These segmental duplications on chromosome 8p23.1 are known to be involved in chromosomal rearrangements because of mutual homology and homology to other genomic regions. Genomic instability mediated by these segmental duplications is generally caused by non-allelic homologous recombination, resulting in deletions, reciprocal duplications, inversions and translocations. Additional analysis of the parental origin of the fragments of this atypical inverted duplication/interstitial deletion shows paternal contribution in the maternal derivate chromosome 8. Combined with the finding that the normal chromosome 8 carries an inversion in 8p23.1 we hypothesize that a double strand break in 8p23.1 of the maternal chromosome was postzygotically repaired with the paternal inverted copy resulting in a duplication, deletion and segmental uniparental disomy, with no particular mediation of the 8p23.1 segmental duplication regions in recombination.

      PubDate: 2017-06-12T01:39:46Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.81.131.189
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016