Genetic Variant GJB2:p.Val13CysfsTer35 (chr13-20189546-A-AC) – ACMG Classification: Pathogenic (16 pts)

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_004004.6(GJB2):c.35dupG(p.Val13CysfsTer35) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000151 in 1,461,606 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

GJB2
NM_004004.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:15

Conservation

PhyloP100: 7.85

Variant links:

Genes affected

GJB2 (HGNC:4284): (gap junction protein beta 2) This gene encodes a member of the gap junction protein family. The gap junctions were first characterized by electron microscopy as regionally specialized structures on plasma membranes of contacting adherent cells. These structures were shown to consist of cell-to-cell channels that facilitate the transfer of ions and small molecules between cells. The gap junction proteins, also known as connexins, purified from fractions of enriched gap junctions from different tissues differ. According to sequence similarities at the nucleotide and amino acid levels, the gap junction proteins are divided into two categories, alpha and beta. Mutations in this gene are responsible for as much as 50% of pre-lingual, recessive deafness. [provided by RefSeq, Oct 2008]

GJB2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 80 pathogenic variants in the truncated region.

PP5

Variant 13-20189546-A-AC is Pathogenic according to our data. Variant chr13-20189546-A-AC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 94392.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJB2	NM_004004.6 link	c.35dupG	p.Val13CysfsTer35	frameshift_variant	Exon 2 of 2	ENST00000382848.5	NP_003995.2	P29033H9U1J4
GJB2	XM_011535049.3 link	c.35dupG	p.Val13CysfsTer35	frameshift_variant	Exon 2 of 2		XP_011533351.1	P29033H9U1J4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJB2	ENST00000382848.5 link	c.35dupG	p.Val13CysfsTer35	frameshift_variant	Exon 2 of 2	1	NM_004004.6	ENSP00000372299.4		P29033
GJB2	ENST00000382844.2 link	c.35dupG	p.Val13CysfsTer35	frameshift_variant	Exon 1 of 1	6		ENSP00000372295.1		P29033

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000241

AC:

AN:

249362

Hom.:

AF XY:

0.0000296

AC XY:

AN XY:

134954

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000867

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000896

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1461606

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

727100

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.000112

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000989

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Bravo

AF:

0.0000151

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:15

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:7

Oct 27, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift variant predicted to result in protein truncation, as the last 214 amino acids are replaced with 34 different amino acids, and other loss-of-function variants have been reported downstream in the Human Gene Mutation Database (HGMD); This variant is associated with the following publications: (PMID: 9482292, 29754767, 31589614, 31541171, 29871260, 32645618, 31160754, 34416374, 23638949, 20639189, 24503448) -

Jan 10, 2023

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is expected to result in the loss of a functional protein. The frequency of this variant in the general population is consistent with pathogenicity. (Genome Aggregation Database (gnomAD), Cambridge, MA (URL: http://gnomad.broadinstitute.org)) In multiple individuals with nonsyndromic hearing loss, this variant has been seen with a single recessive pathogenic variant in the same gene. In some published literature, this variant is referred to as c.35insG. -

Aug 28, 2012

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 23, 2016

Knight Diagnostic Laboratories, Oregon Health and Sciences University

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 01, 2021

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 29, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Val13Cysfs*35) in the GJB2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 214 amino acid(s) of the GJB2 protein. This variant is present in population databases (rs398123814, gnomAD 0.01%). This premature translational stop signal has been observed in individuals with autosomal recessive deafness (PMID: 11439000, 18519481, 19366456, 20497192, 23638949, 24503448). It has also been observed to segregate with disease in related individuals. This variant is also known as 35insG. ClinVar contains an entry for this variant (Variation ID: 94392). For these reasons, this variant has been classified as Pathogenic. -

Nov 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Autosomal recessive nonsyndromic hearing loss 1A

Pathogenic:5

Oct 24, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Feb 09, 2021

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GJB2 c.35dupG (p.Val13CysfsX35) results in a premature termination codon, predicted to cause a truncation, which is a commonly known mechanism for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 2.4e-05 in 249362 control chromosomes (gnomAD). c.35dupG has been reported in the literature in several individuals affected with Autosomal Recessive Non-Syndromic Hearing Loss (e.g. Rabionet_2000, D'Andrea_2002, Dai_2009, Hjelm_2010, Godbole_2010, Bazazzadegan_2012, Usami_2012, Banjara_2015, Liu_2020). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Eight other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Based on the evidence outlined above, the variant was classified as pathogenic. -

Feb 26, 2019

Genetic Testing Center for Deafness, Department of Otolaryngology Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: case-control

- -

Feb 05, 2015

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

Jul 01, 2021

WangQJ Lab, Chinese People's Liberation Army General Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Hearing loss

Pathogenic:1

Jan 22, 2009

Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Hearing impairment

Pathogenic:1

Apr 12, 2021

Department of Otolaryngology – Head & Neck Surgery, Cochlear Implant Center

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1_Strong, PM2_Moderate, BP5_Supporting -

Rare genetic deafness

Pathogenic:1

Nov 30, 2016

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Val13fs variant in GJB2, also reported as c.35dupG or c.35insG, has been r eported in >5 individuals with hearing loss who were compound heterozygous for a second pathogenic variant in GJB2 (Estivill 1998, Huang 2014, Snoeckx 2005, Tsu kada 2010). It has been identified in 6/250260 of the total chromosomes in the genome Aggregation Database (http://gnomad.broadinstitute.org/, dbSNP rs39812381 4). This low frequency in the general population is consistent with the carrier frequency for autosomal recessive hearing loss. This variant is predicted to ca use a frameshift, which alters the protein?s amino acid sequence beginning at po sition 13 and leads to a premature termination codon 35 amino acids downstream. In summary, this variant meets criteria to be classified as pathogenic for autos omal recessive hearing loss based on the predicted impact to the protein and mul tiple previously reported affected compound heterozygotes. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

13-20189546-AC-ACC

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over