scholarly journals Identification of the First Single GSDME Exon 8 Structural Variants Associated with Autosomal Dominant Hearing Loss

Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 207
Author(s):  
Luke Mansard ◽  
Christel Vaché ◽  
Julie Bianchi ◽  
Corinne Baudoin ◽  
Isabelle Perthus ◽  
...  

GSDME, also known as DFNA5, is a gene implicated in autosomal dominant nonsyndromic hearing loss (ADNSHL), affecting, at first, the high frequencies with a subsequent progression over all frequencies. To date, all the GSDME pathogenic variants associated with deafness lead to skipping of exon 8. In two families with apparent ADNSHL, massively parallel sequencing (MPS) integrating a coverage-based method for detection of copy number variations (CNVs) was applied, and it identified the first two causal GSDME structural variants affecting exon 8. The deleterious impact of the c.991-60_1095del variant, which includes the acceptor splice site sequence of exon 8, was confirmed by the study of the proband’s transcripts. The second mutational event is a complex rearrangement that deletes almost all of the exon 8 sequence. This study increases the mutational spectrum of the GSDME gene and highlights the crucial importance of MPS data for the detection of GSDME exon 8 deletions, even though the identification of a causal single-exon CNV by MPS analysis is still challenging.

Author(s):  
Muhammad Noman ◽  
Shazia Anwer Bukhari ◽  
Muhammad Tahir ◽  
Shehbaz Ali

Hearing impairment is an immensely diagnosed genetic cause, 5% of the total world population effects with different kind of congenital hearing loss (HL). In third-world countries or countries where consanguineous marriages are more common the frequency rate of genetic disorders are at its zenith. Approximately, the incidence of hearing afflictions is ostensibly 7-8:1000 individuals whereas it is estimated that about 466 million peoples suffer with significant HL, and of theses deaf cases 34 million are children’s up to March, 2020. Several genes and colossal numbers of pathogenic variants cause hearing impairment, which aided in next-generation with recessive, dominant or X-linked inheritance traits. This review highlights on syndromic and non-syndromic HL (SHL and NSHL), and categorized as conductive, sensorineural and mixed HL, which having autosomal dominant and recessive, and X-linked or mitochondrial mode of inheritance. Many hundred genes involved in HL are reported, and their mutation spectrum becomes very wide. Mapping of pathogenic genes in consanguinity family is facilitated to understand the disease history. Review presents the bases of HL and also focused on various genetic factors that cause deafness like the basics of genetic inheritance, and classic and well-characterized inherited factors of it. It also overviews the application of linkage analysis, SNPs genotyping and whole exome sequencing methods, in mapping and identification of new locus, causative genes and their variants in families inherited with HL. Conclusively, this review supports researchers in understanding the location of chromosome, the causative genes and specific locus which causing deafness in humans.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Tian-Yi Cui ◽  
Xue Gao ◽  
Sha-Sha Huang ◽  
Yan-Yan Sun ◽  
Si-Qi Zhang ◽  
...  

Hereditary hearing loss is one of the most common sensory disabilities worldwide. Mutation of POU domain class 4 transcription factor 3 (POU4F3) is considered the pathogenic cause of autosomal dominant nonsyndromic hearing loss (ADNSHL), designated as autosomal dominant nonsyndromic deafness 15. In this study, four novel variants in POU4F3, c.696G>T (p.Glu232Asp), c.325C>T (p.His109Tyr), c.635T>C (p.Leu212Pro), and c.183delG (p.Ala62Argfs∗22), were identified in four different Chinese families with ADNSHL by targeted next-generation sequencing and Sanger sequencing. Based on the American College of Medical Genetics and Genomics guidelines, c.183delG (p.Ala62Argfs∗22) is classified as a pathogenic variant, c.696G>T (p.Glu232Asp) and c.635T>C (p.Leu212Pro) are classified as likely pathogenic variants, and c.325C>T (p.His109Tyr) is classified as a variant of uncertain significance. Based on previous reports and the results of this study, we speculated that POU4F3 pathogenic variants are significant contributors to ADNSHL in the East Asian population. Therefore, screening of POU4F3 should be a routine examination for the diagnosis of hereditary hearing loss.


2021 ◽  
Author(s):  
Shin-ya Nishio ◽  
Shin-ichi Usami

Abstract TMC1 is a causative gene for both autosomal dominant non-syndromic hearing loss (DFNA36) and autosomal recessive non-syndromic hearing loss (DFNB7/11). To date, 125 pathogenic variants in TMC1 have been reported. Most of the TMC1 variants are responsible for autosomal recessive hearing loss, with only 7 variants reported as causative for DFNA36. Here we reported the prevalence of TMC1-associated hearing loss in a large non-syndromic hearing loss cohort of about 12,000 subjects. As a result, we identified 26 probands with TMC1-associated hearing loss and the estimated prevalence of TMC1-associated hearing loss in the Japanese hearing loss cohort to be 0.18% among all patients. Among the 26 probands with TMC1-associated hearing loss, 15 cases were identified from autosomal dominant hearing loss families. By using the audiometric data from the probands, family members and previously reported cases, we evaluated the hearing deterioration speed for DFNA36 patients. In addition, we performed haplotype analysis for 11 unrelated autosomal dominant hearing loss families carrying the same variant TMC1: NM_138691:c.1627G > A:p.D543N. The results clearly indicated that the same haplotype was present despite of families being unrelated, supporting the contention that this variant occurred by founder mutation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dominika Oziębło ◽  
Marcin L. Leja ◽  
Michal Lazniewski ◽  
Anna Sarosiak ◽  
Grażyna Tacikowska ◽  
...  

AbstractSeveral TBC1D24 variants are causally involved in the development of profound, prelingual hearing loss (HL) and different epilepsy syndromes inherited in an autosomal recessive manner. Only two TBC1D24 pathogenic variants have been linked with postlingual progressive autosomal dominant HL (ADHL). To determine the role of TBC1D24 in the development of ADHL and to characterize the TBC1D24-related ADHL, clinical exome sequencing or targeted multigene (n = 237) panel were performed for probands (n = 102) from multigenerational ADHL families. In four families, TBC1D24-related HL was found based on the identification of three novel, likely pathogenic (c.553G>A, p.Asp185Asn; c.1460A>T, p. His487Leu or c.1461C>G, p.His487Gln) and one known (c.533C>T, p.Ser178Leu) TBC1D24 variant. Functional consequences of these variants were characterized by analyzing the proposed homology models of the human TBC1D24 protein. Variants not only in the TBC (p.Ser178Leu, p.Asp185Asn) but also in the TLDc domain (p.His487Gln, p.His487Leu) are involved in ADHL development, the latter two mutations probably affecting interactions between the domains. Clinically, progressive HL involving mainly mid and high frequencies was observed in the patients (n = 29). The progression of HL was calculated by constructing age-related typical audiograms. TBC1D24-related ADHL originates from the cochlear component of the auditory system, becomes apparent usually in the second decade of life and accounts for approximately 4% of ADHL cases. Given the high genetic heterogeneity of ADHL, TBC1D24 emerges as an important contributor to this type of HL.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kunjing Gong ◽  
Min Xia ◽  
Yaqin Wang ◽  
Na Wang ◽  
Ying Liu ◽  
...  

AbstractGenes of UMOD, HNF1B, MUC1, REN and SEC61A1 were reported to be associated with autosomal dominant tubulointerstitial kidney disease (ADTKD). 48 probands and their family members (N = 27) were enrolled in this genetic screening study. A combination of methods was employed for comprehensive molecular analysis of both copy number variations (CNVs) and single nucleotide variants (SNVs). 35 probands were followed for years. The phenotype-genotype and genotype-outcome correlation were inferred from these datasets. In this cohort, 18 probands were diagnosed with ADTKD, according to Kidney Disease: Improving Global Outcomes (KDIGO) guideline. Moreover, 11 probands were diagnosed with ADTKD-UMOD, one with ADTKD-REN and one with ADTKD-HNF1B, based on molecularly confirmed pathogenic variants. The 11 UMOD variants were mainly located in codons 28 to 289 and half of the variants were found to change the cysteine amino acid. According to the follow-up data, suspected ADTKD individuals had a better prognosis compared to ADTKD individuals (p = 0.029). Individuals with a cysteine substitution in the UMOD gene appeared to have a better prognosis than individuals with other amino acid substitutions (p = 0.015).


2021 ◽  
Author(s):  
Shin-ya Nishio ◽  
Shin-ichi Usami

AbstractTMC1 is a causative gene for both autosomal dominant non-syndromic hearing loss (DFNA36) and autosomal recessive non-syndromic hearing loss (DFNB7/11). To date, 125 pathogenic variants in TMC1 have been reported. Most of the TMC1 variants are responsible for autosomal recessive hearing loss, with only 8 variants reported as causative for DFNA36. Here, we reported the prevalence of TMC1-associated hearing loss in a large non-syndromic hearing loss cohort of about 12,000 subjects. As a result, we identified 26 probands with TMC1-associated hearing loss, with the estimated prevalence of TMC1-associated hearing loss in the Japanese hearing loss cohort being 0.17% among all patients. Among the 26 probands with TMC1-associated hearing loss, 15 cases were identified from autosomal dominant hearing loss families. Based on the audiometric data from the probands, family members and previously reported cases, we evaluated hearing deterioration for DFNA36 patients. In addition, we performed haplotype analysis for 11 unrelated autosomal dominant hearing loss families carrying the same variant TMC1: NM_138691:c.1627G > A:p.Asp543Asn. The results clearly indicated that the same haplotype was present despite the families being unrelated, supporting the contention that this variant occurred by founder mutation.


2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 474-474
Author(s):  
Amin Nassar ◽  
Kent William Mouw ◽  
Edward D. Esplin ◽  
Shan Yang ◽  
Tom Callis ◽  
...  

474 Background: UC is associated with germline alterations in a small minority of patients (pts). The prevalence of germline alterations in those with familial UC is unknown. We identified genomic alterations among familial UC pts to provide insights into pathogenesis and improve management. Methods: We analyzed deidentified data for UC pts with germline multigene panel testing (Invitae) who had a family history of UC, defined as a 1st-3rd degree relative with UC. Massively parallel sequencing used customized capture bait-sets to analyze exonic regions, flanking intronic sequences, and copy number variations (CNVs) for 1-126 genes. Pathogenic and likely pathogenic (P/LP) variants underwent orthogonal confirmation, per standard policy, including single nucleotide variants (SNVs)/small indels/CNVs. Patient characteristics were compared using the Fisher’s Exact and Wilcoxon-Rank Sum test. Results: 79 UC pts with a family history of UC were identified (67 bladder, 6 upper tract, 6 unknown). Six patients (8%) were excluded as the relation of the family member was unknown. 48/73 (66%) pts had first-degree relatives (fdr) with UC (4 upper tract, 39 bladder, 5 unknown) and 25 (34%) had second-degree (or higher) relatives (sdr) (2 upper tract, 22 bladder, 1 unknown). 56 germline alterations were found in 38 (52%) pts. 14 known pathogenic alterations occurred in 13 (18%) pts: SDHC (1), MITF (2), BRIP1 (1), BRCA2 (1), MSH2 (3), BRCA1 (1), CHEK2 (1), PTCH (1), MUTYH (2), BAP1 (1). 8/48 (17%) pts with fdr had pathogenic variants vs. 5/25 (20%) pts with sdr or more. There was no difference in the prevalence of pathogenic variants based on gender (p=0.37) or age (p=0.77). The limitations are modest sample size and differences in panels of genes. Conclusions: This is the first study to our knowledge to report germline alterations in UC pts with a family history of UC. Pathogenic germline alterations were seen in 18% of pts, which were enriched for DNA damage repair gene alterations, and could have important therapeutic implications. Further study of germline alterations using larger panels in pts with family history of UC may provide novel insights, since most pts did not have pathogenic alterations.


2020 ◽  
Vol 29 (9) ◽  
pp. 1520-1536 ◽  
Author(s):  
Karina Lezirovitz ◽  
Gleiciele A Vieira-Silva ◽  
Ana C Batissoco ◽  
Débora Levy ◽  
Joao P Kitajima ◽  
...  

Abstract Here we define a ~200 Kb genomic duplication in 2p14 as the genetic signature that segregates with postlingual progressive sensorineural autosomal dominant hearing loss (HL) in 20 affected individuals from the DFNA58 family, first reported in 2009. The duplication includes two entire genes, PLEK and CNRIP1, and the first exon of PPP3R1 (protein coding), in addition to four uncharacterized long non-coding (lnc) RNA genes and part of a novel protein-coding gene. Quantitative analysis of mRNA expression in blood samples revealed selective overexpression of CNRIP1 and of two lncRNA genes (LOC107985892 and LOC102724389) in all affected members tested, but not in unaffected ones. Qualitative analysis of mRNA expression identified also fusion transcripts involving parts of PPP3R1, CNRIP1 and an intergenic region between PLEK and CNRIP1, in the blood of all carriers of the duplication, but were heterogeneous in nature. By in situ hybridization and immunofluorescence, we showed that Cnrip1, Plek and Ppp3r1 genes are all expressed in the adult mouse cochlea including the spiral ganglion neurons, suggesting changes in expression levels of these genes in the hearing organ could underlie the DFNA58 form of deafness. Our study highlights the value of studying rare genomic events leading to HL, such as copy number variations. Further studies will be required to determine which of these genes, either coding proteins or non-coding RNAs, is or are responsible for DFNA58 HL.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Surajit Bhattacharya ◽  
Hayk Barseghyan ◽  
Emmanuèle C. Délot ◽  
Eric Vilain

Abstract Background Whole genome sequencing is effective at identification of small variants, but because it is based on short reads, assessment of structural variants (SVs) is limited. The advent of Optical Genome Mapping (OGM), which utilizes long fluorescently labeled DNA molecules for de novo genome assembly and SV calling, has allowed for increased sensitivity and specificity in SV detection. However, compared to small variant annotation tools, OGM-based SV annotation software has seen little development, and currently available SV annotation tools do not provide sufficient information for determination of variant pathogenicity. Results We developed an R-based package, nanotatoR, which provides comprehensive annotation as a tool for SV classification. nanotatoR uses both external (DGV; DECIPHER; Bionano Genomics BNDB) and internal (user-defined) databases to estimate SV frequency. Human genome reference GRCh37/38-based BED files are used to annotate SVs with overlapping, upstream, and downstream genes. Overlap percentages and distances for nearest genes are calculated and can be used for filtration. A primary gene list is extracted from public databases based on the patient’s phenotype and used to filter genes overlapping SVs, providing the analyst with an easy way to prioritize variants. If available, expression of overlapping or nearby genes of interest is extracted (e.g. from an RNA-Seq dataset, allowing the user to assess the effects of SVs on the transcriptome). Most quality-control filtration parameters are customizable by the user. The output is given in an Excel file format, subdivided into multiple sheets based on SV type and inheritance pattern (INDELs, inversions, translocations, de novo, etc.). nanotatoR passed all quality and run time criteria of Bioconductor, where it was accepted in the April 2019 release. We evaluated nanotatoR’s annotation capabilities using publicly available reference datasets: the singleton sample NA12878, mapped with two types of enzyme labeling, and the NA24143 trio. nanotatoR was also able to accurately filter the known pathogenic variants in a cohort of patients with Duchenne Muscular Dystrophy for which we had previously demonstrated the diagnostic ability of OGM. Conclusions The extensive annotation enables users to rapidly identify potential pathogenic SVs, a critical step toward use of OGM in the clinical setting.


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