NM_004004.6:c.246C>G

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM5PP2PP3_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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I82T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

GJB2
NM_004004.6 missense

Scores

13
5
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 4.83

Publications

13 publications found
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 Gene-Disease associations (from GenCC):
  • Bart-Pumphrey syndrome
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
  • ichthyosis, hystrix-like, with hearing loss
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
  • keratoderma hereditarium mutilans
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, G2P
  • palmoplantar keratoderma-deafness syndrome
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
  • autosomal recessive nonsyndromic hearing loss 1A
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, G2P, PanelApp Australia
  • hearing loss, autosomal recessive
    Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
  • autosomal dominant keratitis-ichthyosis-hearing loss syndrome
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics
  • autosomal dominant nonsyndromic hearing loss 3A
    Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • autosomal dominant nonsyndromic hearing loss
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • KID syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 23 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 8 uncertain in NM_004004.6
PM5
Other missense variant is known to change same aminoacid residue: Variant chr13-20189338-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 599264.Status of the report is criteria_provided_single_submitter, 1 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 111 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: -0.72044 (below the threshold of 3.09). Trascript score misZ: 0.4379 (below the threshold of 3.09). GenCC associations: The gene is linked to autosomal recessive nonsyndromic hearing loss 1A, ichthyosis, hystrix-like, with hearing loss, keratoderma hereditarium mutilans, hearing loss, autosomal recessive, Bart-Pumphrey syndrome, palmoplantar keratoderma-deafness syndrome, autosomal dominant keratitis-ichthyosis-hearing loss syndrome, autosomal dominant nonsyndromic hearing loss 3A, autosomal dominant nonsyndromic hearing loss, KID syndrome.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.993
PP5
Variant 13-20189336-G-C is Pathogenic according to our data. Variant chr13-20189336-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 188756.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
GJB2NM_004004.6 linkc.246C>G p.Ile82Met missense_variant Exon 2 of 2 ENST00000382848.5 NP_003995.2 P29033H9U1J4
GJB2XM_011535049.3 linkc.246C>G p.Ile82Met missense_variant Exon 2 of 2 XP_011533351.1 P29033H9U1J4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GJB2ENST00000382848.5 linkc.246C>G p.Ile82Met missense_variant Exon 2 of 2 1 NM_004004.6 ENSP00000372299.4 P29033
GJB2ENST00000382844.2 linkc.246C>G p.Ile82Met missense_variant Exon 1 of 1 6 ENSP00000372295.1 P29033
ENSG00000296095ENST00000736390.1 linkn.232-3756C>G intron_variant Intron 1 of 3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152208
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000796
AC:
2
AN:
251372
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000171
AC:
25
AN:
1461814
Hom.:
0
Cov.:
33
AF XY:
0.0000138
AC XY:
10
AN XY:
727206
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53352
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000216
AC:
24
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152208
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74362
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41450
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive nonsyndromic hearing loss 1A Pathogenic:3
Jan 27, 2021
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Mar 25, 2019
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.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. -

Apr 10, 2014
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

not provided Pathogenic:2
Sep 30, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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) -

Dec 03, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. -

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
May 17, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nonsyndromic genetic hearing loss Pathogenic:1
Aug 21, 2020
INGEBI, INGEBI / CONICET
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
May 27, 2024
PreventionGenetics, part of Exact Sciences
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.68
BayesDel_addAF
Pathogenic
0.53
D
BayesDel_noAF
Pathogenic
0.54
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.93
D;D;D
Eigen
Pathogenic
0.84
Eigen_PC
Pathogenic
0.79
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.93
.;.;D
M_CAP
Pathogenic
0.50
D
MetaRNN
Pathogenic
0.99
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.6
H;H;H
PhyloP100
4.8
PrimateAI
Uncertain
0.77
T
PROVEAN
Uncertain
-3.0
D;D;.
REVEL
Pathogenic
0.93
Sift
Pathogenic
0.0
D;D;.
Sift4G
Pathogenic
0.0
D;D;.
Polyphen
1.0
D;D;D
Vest4
0.97
MutPred
0.95
Loss of stability (P = 0.0202);Loss of stability (P = 0.0202);Loss of stability (P = 0.0202);
MVP
0.97
MPC
0.28
ClinPred
0.99
D
GERP RS
5.3
PromoterAI
-0.046
Neutral
Varity_R
0.93
gMVP
0.92
Mutation Taster
=1/99
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs781534323; hg19: chr13-20763475; API