rs781534323
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PP3_StrongPP5_Very_Strong
The NM_004004.6(GJB2):c.246C>G(p.Ile82Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000161 in 1,614,022 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_004004.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152208Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.00000796 AC: 2AN: 251372Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135868
GnomAD4 exome AF: 0.0000171 AC: 25AN: 1461814Hom.: 0 Cov.: 33 AF XY: 0.0000138 AC XY: 10AN XY: 727206
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152208Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74362
ClinVar
Submissions by phenotype
Autosomal recessive nonsyndromic hearing loss 1A Pathogenic:3
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Variant summary: GJB2 c.246C>G (p.Ile82Met) results in a conservative amino acid change located in the transmembrane domain (Palmada 2006) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8.1e-06 in 246170 control chromosomes (gnomAD). c.246C>G has been reported in the literature in multiple compound heterozygous individuals affected with Non-Syndromic Hearing Loss (Kupka 2002, Bartsch 2010, Danilenko 2012, Snoeckx 2005). These data indicate that the variant is very likely to be associated with disease. At least one publication reported experimental evidence evaluating an impact on protein function, demonstrating profound reduction in channel activity as determined by electrophysiological analysis on Xenopus oocytes expressing the mutant protein (Palmada 2006). No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided Pathogenic:2
This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 82 of the GJB2 protein (p.Ile82Met). This variant is present in population databases (rs781534323, gnomAD 0.002%). This missense change has been observed in individuals with autosomal recessive deafness (PMID: 12112666, 15964725, 20234132, 22567152). ClinVar contains an entry for this variant (Variation ID: 188756). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt GJB2 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GJB2 function (PMID: 16300957). For these reasons, this variant has been classified as Pathogenic. -
Published functional studies demonstrate a damaging effect on protein function due to a reduction of channel activation and possible dominant negative effect on wild-type protein (PMID: 16300957); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 12112666, 25388846, 16380907, 19887791, 15964725, 20234132, 33096615, 36048236, 34308104, 16300957) -
Autosomal dominant keratitis-ichthyosis-hearing loss syndrome;C0265964:Mutilating keratoderma;C0266004:Knuckle pads, deafness AND leukonychia syndrome;C1835672:Palmoplantar keratoderma-deafness syndrome;C1865234:Ichthyosis, hystrix-like, with hearing loss;C2673759:Autosomal recessive nonsyndromic hearing loss 1A;C2675750:Autosomal dominant nonsyndromic hearing loss 3A Pathogenic:1
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Nonsyndromic genetic hearing loss Pathogenic:1
Based on ACMG/AMP guidelines and Hearing Loss Expert Panel specific criteria: the c.246C>G, p.Ile82Met is only present in european non-finish population with a filtering variant frequency of 0,00031% from Genome Aggregation Database v2.1.1 (http://gnomad.broadinstitute.org; calculated by using inverse allele frequency at https://www.cardiodb.org/allelefrequencyapp/) meeting PM2. This variant was identified in trans with several pathogenic variants at least four times applying to PM3_VeryStrong (PMID:15964725,16380907,12112666). Besides, p.Ile82Met change in trans with c.35delG variant segregated in two affected meeting PP1_Moderate criteria (PMID: 12112666). Computational evidence showed a damage impact of the mutation to the protein (REVEL: 0.928) meeting PP3 rule. Functional studies in Xenopus Laevis oocytes demonstrated a deleterious effect since there was a significantly decrease of current measure when p.Ile82Met was injected compared to wild type channels (PMID: 16300957) applying to PS3_Moderate. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive nonsyndromic hearing loss (PM2, PP1_Moderate, PM3_VeryStrong, PP3 and PS3_Moderate). -
GJB2-related disorder Pathogenic:1
The GJB2 c.246C>G variant is predicted to result in the amino acid substitution p.Ile82Met. This variant was reported in at least two individuals with autosomal recessive nonsyndromic hearing loss in the compound heterozygous state along with a second pathogenic variant (Kupka. 2002. PubMed ID: 12112666; Dalamón. 2005. PubMed ID: 15964725). In vitro experiments demonstrated this variant impairs protein function (Palmada. 2005. PubMed ID: 16300957). This variant is reported in 0.0018% of alleles in individuals of European (Non-Finnish) descent in gnomAD. This variant is interpreted as likely pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at