Submissions for variant NM_004004.6(GJB2):c.11del (p.Gly4fs)

dbSNP: rs1555342014

Total submissions: 4

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV000588025	SCV000698226	likely pathogenic	Autosomal recessive nonsyndromic hearing loss 1A	2016-04-05	criteria provided, single submitter	clinical testing	Variant summary: This GJB2 c.11delG variant causes a frameshift, which alters the proteins amino acid sequence beginning at position 4 and leads to a premature termination codon nine amino acids downstream. Mutation taster predicts this variant to be disease-causing. The variant was not observed in the large and broad cohorts of the ExAC project or ESP. The variant of interest was reported in 2 patients with hearing loss (Putcha_GenMed_2007, Banjara_IJOHNS_2015). Truncations downstream of this position have been classified as disease/pathogenic variants by our laboratory such as c.19C>T (p.Gln7X ), c.35dupG (V13fs), and c.35delG (G12fs). Deafness variation database lists the variant as "pathogenic." Considering all evidence, this variant has been classified as Likely Pathogenic until additional information becomes available.
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	RCV001002185	SCV001160056	pathogenic	not specified	2018-10-21	criteria provided, single submitter	clinical testing	The GJB2 c.11delG; p.Gly4fs variant, also published as 8delG, is reported in the medical literature in at least two individuals with hearing loss (Banjara 2016, Putcha 2007). The variant is reported in the ClinVar database (Variation ID: 496214), but is absent from general population databases (1000 Genomes Project, Exome Variant Server, and Genome Aggregation Database), indicating it is not a common polymorphism. This variant causes a frameshift by deleting a single nucleotide, so it is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Additionally, the variant is classified as pathogenic in the Deafness Variation Database (see link below) and other frameshift variants in this region are classified as pathogenic (see link to ClinVar below). Considering available information, this variant is classified as pathogenic. References: Link to Deafness Variation Database: http://deafnessvariationdatabase.org Link to GJB2 in ClinVar: http://www.ncbi.nlm.nih.gov/clinvar/?term=GJB2%5Bgene%5D Banjara H et al. Detection of Connexion 26 GENE (GJB2) Mutations in Cases of Congenital Non Syndromic Deafness. Indian J Otolaryngol Head Neck Surg. 2016 Jun;68(2):248-53. Putcha GV et al. A multicenter study of the frequency and distribution of GJB2 and GJB6 mutations in a large North American cohort. Genet Med. 2007 Jul;9(7):413-26.
GeneDx	RCV002272297	SCV002558153	likely pathogenic	not provided	2022-02-01	criteria provided, single submitter	clinical testing	Observed in a patient with hearing loss in published literature; however, no specific information on the patient is available (Putcha GV et al., 2007); Frameshift variant predicted to result in protein truncation, as the last 223 amino acids are replaced with 9 different amino acids, and other loss-of-function variants have been reported downstream in HGMD; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 17666888)
Labcorp Genetics (formerly Invitae), Labcorp	RCV002272297	SCV004295459	pathogenic	not provided	2023-10-04	criteria provided, single submitter	clinical testing	This sequence change creates a premature translational stop signal (p.Gly4Alafs*10) in the GJB2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 223 amino acid(s) of the GJB2 protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with deafness (PMID: 17666888). ClinVar contains an entry for this variant (Variation ID: 496214). This variant disrupts a region of the GJB2 protein in which other variant(s) (p.Leu213*) have been determined to be pathogenic (PMID: 23141775). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.