scholarly journals Putative Digenic GJBI2/MYO7A Inheritance of Hearing Loss Detected in a Patient with 48, XXYY Klinefelter Syndrome

2020 ◽  
Author(s):  
Tian-tian Qin ◽  
Qin Zhang ◽  
Wen-mu Hu ◽  
Muhammad Usman Janjua ◽  
Qin Long ◽  
...  

Abstract Background: 48, XXYY Klinefelter syndrome is a rare sex chromosome abnormality. Nonsyndromic hearing loss (NSHL) is the most frequent hereditary type of hearing impairment. There has been no report of NSHL combined with 48XXYY. The purpose of this study was to explore the underlying genetic cause in a three-generation family affected by NSHL. The proband had concomitant NSHL and 48, XXYY syndrome. The whole-exome sequencing was performed in the proband. The candidate pathogenic variants identified by whole-exome sequencing were then confirmed by Sanger sequencing and segregation analysis.Results: The proband was identified to be compound heterozygous for c.109G>A (p.V37I) variant in the GJB2 gene and additional heterozygous for the c.1039C>A (p.L347I) variants in the MYO7A gene. His mother had normal hearing and did not have any form of variant. His father and uncle, both had NSHL, were digenic compound heterozygote for the GJB2 p.V37I and MYO7A p.L347I variants, thus suggesting a possible GJB2/MYO7A digenic inheritance of NSHL in this family consist with the clinical phenotype.Conclusions: Our findings reported a putative GJB2/MYO7A digenic inheritance form of hearing loss, which expands the mutation spectrum of NSHL. This is also the first report of concomitant NSHL and 48, XXYY syndrome.

2021 ◽  
pp. 1-7
Author(s):  
Qin Zhang ◽  
Tiantian Qin ◽  
Wenmu Hu ◽  
Muhammad Usman Janjua ◽  
Ping Jin

<b><i>Objectives:</i></b> Nonsyndromic hearing loss (NSHL) is the most frequent type of hereditary hearing impairment. Here, we explored the underlying genetic cause of NSHL in a three-generation family using whole-exome sequencing. The proband had concomitant NSHL and rare 48,XXYY Klinefelter syndrome. <b><i>Material and Methods:</i></b> Genomic DNA was extracted from the peripheral blood of the proband and their family members. Sanger sequencing and pedigree verification were performed on the pathogenic variants filtered by whole-exome sequencing. The function of the variants was analyzed using bioinformatics software. <b><i>Results:</i></b> The proband was digenic heterozygous for p.V37I in the <i>GJB2</i> gene and p.L347I in the <i>MYO7A</i> gene. The proband’s mother had normal hearing and did not have any variant. The proband’s father and uncle both had NSHL and were compound for the <i>GJB2</i> p.V37I and <i>MYO7A</i> p.L347I variants, thus indicating a possible <i>GJB2/MYO7A</i> digenic inheritance of NSHL. 48,XXYY Klinefelter syndrome was discovered in the proband after the karyotype analysis, while his parents both had normal karyotypes. <b><i>Conclusions:</i></b> Our findings reported a putative <i>GJB2/MYO7A</i> digenic inheritance form of hearing loss, expanding the genotype and phenotype spectrum of NSHL. In addition, this is the first report of concomitant NSHL and 48,XXYY syndrome.


2021 ◽  
Vol 7 (2) ◽  
pp. e558
Author(s):  
Daphne J. Smits ◽  
Rachel Schot ◽  
Martina Wilke ◽  
Marjon van Slegtenhorst ◽  
Marie Claire Y. de Wit ◽  
...  

ObjectiveWe aimed to identify pathogenic variants in a girl with epilepsy, developmental delay, cerebellar ataxia, oral motor difficulty, and structural brain abnormalities with the use of whole-exome sequencing.MethodsWhole-exome trio analysis and molecular functional studies were performed in addition to the clinical findings and neuroimaging studies.ResultsBrain MRI showed mild pachygyria, hypoplasia of the cerebellar vermis, and abnormal foliation of the cerebellar vermis, suspected for a variant in one of the genes of the Reelin pathway. Trio whole-exome sequencing and additional functional studies were performed to identify the pathogenic variants. Trio whole-exome sequencing revealed compound heterozygous splice variants in DAB1, both affecting the highly conserved functional phosphotyrosine-binding domain. Expression studies in patient-derived cells showed loss of normal transcripts, confirming pathogenicity.ConclusionsWe conclude that these variants are very likely causally related to the cerebral phenotype and propose to consider loss-of-function DAB1 variants in patients with RELN-like cortical malformations.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Takayuki Yokoi ◽  
Yumi Enomoto ◽  
Tomoko Uehara ◽  
Kenjiro Kosaki ◽  
Kenji Kurosawa

AbstractWe report a Japanese girl with mild xeroderma pigmentosum group D neurological disease. She had short stature, cataracts, intellectual disability, and mild skin symptoms. However, she was not clinically diagnosed. Using whole-exome sequencing, we identified compound heterozygous pathogenic variants in ERCC2. In the future, the patient may develop skin cancer and her neurological symptoms may progress. Early genetic testing is necessary to clarify the cause of symptoms in undiagnosed patients.


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Mei Zhao ◽  
Lingling Hou ◽  
Huajing Teng ◽  
Jinchen Li ◽  
Jiesi Wang ◽  
...  

Pathogenic variants in the argininosuccinate lyase (ASL) gene have been shown to cause argininosuccinate lyase deficiency (ASLD); therefore, sequencing analysis offers advantages for prenatal testing and counseling in families afflicted with this condition. Here, we performed a genetic analysis of an ASLD patient and his family with an aim to offer available information for clinical diagnosis. The research subjects were a 23-month-old patient with a high plasma level of citrulline and his unaffected parents. Whole-exome sequencing identified potential related ASL gene mutations in this trio. Enzymatic activity was detected spectrophotometrically by a coupled assay using arginase and measuring urea production. We identified a novel nonsynonymous mutation (c.206A>G, p.Lys69Arg) and a stop mutation (c.637C>T, p.Arg213∗) in ASL in a Chinese Han patient with ASLD. The enzymatic activity of a p.Lys69Arg ASL construct in human embryonic kidney 293T cells was significantly reduced compared to that of the wild-type construct, and no significant activity was observed for the p.Arg213∗ construct. Compound heterozygous p.Lys69Arg and p.Arg213∗ mutations that resulted in reduced ASL enzyme activity were found in a patient with ASLD. This finding expands the clinical spectrum of ASL pathogenic variants.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Hosneara Akter ◽  
Mohammad Shahnoor Hossain ◽  
Nushrat Jahan Dity ◽  
Md. Atikur Rahaman ◽  
K. M. Furkan Uddin ◽  
...  

AbstractCollectively, rare genetic diseases affect a significant number of individuals worldwide. In this study, we have conducted whole-exome sequencing (WES) and identified underlying pathogenic or likely pathogenic variants in five children with rare genetic diseases. We present evidence for disease-causing autosomal recessive variants in a range of disease-associated genes such as DHH-associated 46,XY gonadal dysgenesis (GD) or 46,XY sex reversal 7, GNPTAB-associated mucolipidosis II alpha/beta (ML II), BBS1-associated Bardet–Biedl Syndrome (BBS), SURF1-associated Leigh Syndrome (LS) and AP4B1-associated spastic paraplegia-47 (SPG47) in unrelated affected members from Bangladesh. Our analysis pipeline detected three homozygous mutations, including a novel c. 863 G > C (p.Pro288Arg) variant in DHH, and two compound heterozygous variants, including two novel variants: c.2972dupT (p.Met991Ilefs*) in GNPTAB and c.229 G > C (p.Gly77Arg) in SURF1. All mutations were validated by Sanger sequencing. Collectively, this study adds to the genetic heterogeneity of rare genetic diseases and is the first report elucidating the genetic profile of (consanguineous and nonconsanguineous) rare genetic diseases in the Bangladesh population.


2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Qin Xiang ◽  
Yanna Cao ◽  
Hongbo Xu ◽  
Yi Guo ◽  
Zhijian Yang ◽  
...  

Abstract Stargardt disease (STGD1, OMIM 248200) is a common hereditary juvenile or early adult onset macular degeneration. It ultimately leads to progressive central vision loss. Here, we sought to identify gene mutations associated with STGD1 in a three-generation Han Chinese pedigree by whole exome sequencing and Sanger sequencing. Two novel potentially pathogenic variants in a compound heterozygous state, c.3607G>T (p.(Gly1203Trp)) and c.6722T>C (p.(Leu2241Pro)), in the ATP binding cassette subfamily A member 4 gene (ABCA4) were identified as contributing to the family’s STGD1 phenotype. These variants may impact the ABCA4 protein structure and reduce the retinal-activated ATPase activity, leading to abnormal all-trans retinal accumulation in photoreceptor outer segments and in retinal pigment epithelium cells. The present study broadens the mutational spectrum of the ABCA4 responsible for STGD1. A combination of whole exome sequencing and Sanger sequencing is likely to be a time-saving and cost-efficient approach to screen pathogenic variants in genetic disorders caused by sizable genes, as well as avoiding misdiagnosis. These results perhaps refine genetic counseling and ABCA4-targetted treatments for families affected by STGD1.


2019 ◽  
Vol 47 (3) ◽  
pp. 1387-1394 ◽  
Author(s):  
Lin Li ◽  
Jin-Qi Zhao ◽  
Chengrong Wang ◽  
Nan Yang ◽  
Li-Fei Gong ◽  
...  

Objective This study’s aim was to identify the genetic causes in a patient with phenylketonuria and hearing loss, liver disease, developmental and mental retardation, hypotonia, and external ophthalmoplegia. Methods Whole-exome sequencing and Sanger sequencing analysis were used to determine the genetic causes of manifestations in a young boy with hearing loss, liver disease, develop-mental and mental retardation, hypotonia, and external ophthalmoplegia. Results We found that the child harbored polymerase gamma ( POLG) compound heterozygous mutations, c.2617G>A (p.E873K) and c.3550G>A (p.D1184N), and phenylalanine hydroxylase ( PAH) compound heterozygous mutations, c.721C>T (p.R241C) and c.728G>A (p.R243Q). Among them, the POLG p.E873K mutation is a novel mutation and is not present in the Exome Aggregation Consortium database, Genome Aggregation database, and 1000 Genomes database. The two heterozygous mutations were each inherited from both of the child’s parents. This finding suggested that the phenotype and the genotype were segregated. Conclusion Using whole-exome sequencing, we not only identified PAH mutations causing phenylketonuria, but also identified the genetic cause of the mitochondrial disease and found a novel POLG mutation. Our findings could be useful in helping future parents obtain healthy embryos through assisted reproductive technology.


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