rs1326514987

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1PM2PM5PP3_StrongPP5

The ENST00000382848.5(GJB2):​c.133G>A​(p.Gly45Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,612,988 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G45E) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GJB2
ENST00000382848.5 missense

Scores

13
4
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:2

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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PM1
In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 3 uncertain in ENST00000382848.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr13-20189448-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 17033.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.968
PP5
Variant 13-20189449-C-T is Pathogenic according to our data. Variant chr13-20189449-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 556575.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Pathogenic=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
GJB2NM_004004.6 linkuse as main transcriptc.133G>A p.Gly45Arg missense_variant 2/2 ENST00000382848.5 NP_003995.2
GJB2XM_011535049.3 linkuse as main transcriptc.133G>A p.Gly45Arg missense_variant 2/2 XP_011533351.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
GJB2ENST00000382848.5 linkuse as main transcriptc.133G>A p.Gly45Arg missense_variant 2/21 NM_004004.6 ENSP00000372299 P1
GJB2ENST00000382844.2 linkuse as main transcriptc.133G>A p.Gly45Arg missense_variant 1/1 ENSP00000372295 P1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152164
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1460824
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
726506
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152164
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74328
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingGeneDxJul 01, 2024Reported heterozygous in a patient with post-lingual hearing loss in the published literature (PMID: 27761313); however, additional clinical and inheritance information was not provided; Published functional studies demonstrate that the Cx26 protein with this variant is able to formgap junction channels at cell membranes, but channels showreduced IP3 permeability when co-expressed withwildtype Cx26 channels, consistent witha dominant negative effect on channel function (PMID: 27761313); Located in the highly conserved parahelix region of connexin 26; 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: 36048236, 27761313, 37106706, 37892203) -
Likely pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpAug 23, 2021This sequence change replaces glycine with arginine at codon 45 of the GJB2 protein (p.Gly45Arg). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and arginine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with deafness (PMID: 27761313). ClinVar contains an entry for this variant (Variation ID: 556575). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GJB2 protein function. Experimental studies have shown that this missense change affects GJB2 function (PMID: 27761313). This variant disrupts the p.Gly45 amino acid residue in GJB2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15633193, 16885744, 18024254, 24785414). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineJul 25, 2018Variant classified as Uncertain Significance - Favor Pathogenic. The p.Gly45Arg variant in GJB2 has been reported in 1 individual with non-syndromic hearing los s (Rodriguez-Paris 2016). In addition, in vitro fluorescence microscopy studies suggest impaired permeability of IP3 through the connexin-26 (GJB2) channel for the p.Gly45Arg variant, potentially in an autosomal dominant manner (Rodriguez-P aris 2016). This variant has also been identified in 1/8722 of African chromosom es by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org) . Computational prediction tools and conservation analysis suggest that the p.Gl y45Arg variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, while there is some suspicion fo r a pathogenic role, the clinical significance of the p.Gly45Arg variant is unce rtain. ACMG/AMP Criteria applied: PM2; PP3; PS3_Supporting. -
Autosomal recessive nonsyndromic hearing loss 1A Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingCounsylFeb 13, 2018- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.83
BayesDel_addAF
Pathogenic
0.54
D
BayesDel_noAF
Pathogenic
0.53
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.91
D;D;D
Eigen
Pathogenic
0.91
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Benign
0.83
.;.;T
M_CAP
Pathogenic
0.66
D
MetaRNN
Pathogenic
0.97
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.0
M;M;M
MutationTaster
Benign
1.0
D;D
PrimateAI
Uncertain
0.66
T
PROVEAN
Pathogenic
-5.7
D;D;.
REVEL
Pathogenic
0.90
Sift
Uncertain
0.0090
D;D;.
Sift4G
Uncertain
0.011
D;D;.
Polyphen
1.0
D;D;D
Vest4
0.94
MutPred
0.77
Gain of solvent accessibility (P = 0.0306);Gain of solvent accessibility (P = 0.0306);Gain of solvent accessibility (P = 0.0306);
MVP
0.98
MPC
0.30
ClinPred
1.0
D
GERP RS
5.2
Varity_R
0.89
gMVP
0.96

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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.

Other links and lift over

dbSNP: rs1326514987; hg19: chr13-20763588; COSMIC: COSV101241503; COSMIC: COSV101241503; API