13-20189303-C-T

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.279G>A​(p.Met93Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000576 in 1,613,898 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. M93R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000062 ( 0 hom. )

Consequence

GJB2
NM_004004.6 missense

Scores

10
5
4

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 7.86

Publications

10 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 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_004004.6
PM5
Other missense variant is known to change same aminoacid residue: Variant chr13-20189305-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2169572.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, 0.963
PP5
Variant 13-20189303-C-T is Pathogenic according to our data. Variant chr13-20189303-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 44733.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.279G>A p.Met93Ile missense_variant Exon 2 of 2 ENST00000382848.5 NP_003995.2
GJB2XM_011535049.3 linkc.279G>A p.Met93Ile missense_variant Exon 2 of 2 XP_011533351.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GJB2ENST00000382848.5 linkc.279G>A p.Met93Ile missense_variant Exon 2 of 2 1 NM_004004.6 ENSP00000372299.4
GJB2ENST00000382844.2 linkc.279G>A p.Met93Ile missense_variant Exon 1 of 1 6 ENSP00000372295.1
ENSG00000296095ENST00000736390.1 linkn.232-3723G>A intron_variant Intron 1 of 3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152198
Hom.:
0
Cov.:
33
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:
0.0000147
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251190
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.0000615
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:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000616
AC:
90
AN:
1461700
Hom.:
0
Cov.:
33
AF XY:
0.0000564
AC XY:
41
AN XY:
727172
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
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:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53240
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000782
AC:
87
AN:
1112010
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.480
Heterozygous variant carriers
0
6
13
19
26
32
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000197
AC:
3
AN:
152198
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74358
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41444
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
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:
68040
Other (OTH)
AF:
0.000478
AC:
1
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000359
Hom.:
0
Bravo
AF:
0.0000264
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Jan 21, 2024
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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: 18776652, 16380907, 14985372, 25616557, 17666888, 20497192, 20668687, 12172394, 25388846, 22592158, 22695344, 30708180, 24156272, 15666300, 36478599, 30245029, 28483220, 25555641, 25447126) -

Mar 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 93 of the GJB2 protein (p.Met93Ile). This variant is present in population databases (rs397516871, gnomAD 0.004%). This missense change has been observed in individuals with autosomal recessive deafness (PMID: 12172394, 14985372). ClinVar contains an entry for this variant (Variation ID: 44733). 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 with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GJB2 function (PMID: 22592158). This variant disrupts the p.Met93 amino acid residue in GJB2. Other variant(s) that disrupt this residue have been determined to be pathogenic (Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Oct 21, 2021
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The GJB2 c.279G>A; p.Met93Ile variant (rs397516871) is reported in the literature in multiple individuals affected with hearing loss often found with a second pathogenic variant (Cryns 2004, Naghavi 2008, Najmabadi 2005, Putcha 2007, Wu 2002). This variant is also reported in ClinVar (Variation ID: 44733). This variant is found in the non-Finnish European population with an allele frequency of 0.003% (3/113608 alleles) in the Genome Aggregation Database. The methionine at codon 93 is highly conserved, and computational analyses predict that this variant is deleterious (REVEL: 0.874). Based on available information, this variant is considered to be likely pathogenic. References: Cryns K et al. A genotype-phenotype correlation for GJB2 (connexin 26) deafness. J Med Genet. 2004 Mar;41(3):147-54. PMID: 14985372. Naghavi A et al. GJB2 mutations in Baluchi population. J Genet. 2008 Aug;87(2):195-7. PMID: 18776652. Najmabadi H et al. GJB2 mutations: passage through Iran. Am J Med Genet A. 2005 Mar 1;133A(2):132-7. PMID: 15666300. 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. PMID: 17666888. Wu BL et al. Effectiveness of sequencing connexin 26 (GJB2) in cases of familial or sporadic childhood deafness referred for molecular diagnostic testing. Genet Med. 2002 Jul-Aug;4(4):279-88. PMID: 12172394. -

Autosomal recessive nonsyndromic hearing loss 1A Pathogenic:2
Jul 17, 2017
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

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. -

Apr 05, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: GJB2 c.279G>A (p.Met93Ile) results in a conservative amino acid change located in the Connexin, N-terminal domain (IPR013092) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 251190 control chromosomes. c.279G>A has been reported in the literature in individuals affected with Autosomal Recessive Non-Syndromic Hearing Loss (example, Wu_2002, Cryns_2004, Snoeckx_2005, Tsukada_2010). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Autosomal dominant keratitis-ichthyosis-hearing loss syndrome;C0265964:Mutilating keratoderma;C0266004:Knuckle pads, deafness AND leukonychia syndrome;C1835672:Palmoplantar keratoderma-deafness syndrome;C1844678:X-linked mixed hearing loss with perilymphatic gusher;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, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Rare genetic deafness Pathogenic:1
Jun 06, 2017
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Met93Ile variant in GJB2 has been reported in at least 8 individuals with hearing loss including four compound heterozygotes with pathogenic variants in t rans (Wu 2002, Cryns 2004, Najmabadi 2005, Snoeckx 2005, Putcha 2007, Naghavi 20 08, Rodriguez-Paris 2010, Tsukada 2010, LMM data). (Wu 2002, Cryns 2004, Tsukada 2010). The hearing loss described in these four individuals ranged from mild t o moderately-severe (Wu 2002, Cryns 2004, Tsukada 2010, LMM data). This variant has also been identified in 4/126570 European chromosomes by the Genome Aggregat ion Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs397516871). Alth ough this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency for nonsyndromic hear ing loss. Computational prediction tools and conservation analysis suggest that the variant may impact the protein, though this information is not predictive en ough to determine pathogenicity. In summary, although additional studies are req uired to fully establish its clinical significance, the p.Met93Ile variant is li kely pathogenic based on compound heterozygosity in multiple affected individual s. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.37
D
BayesDel_noAF
Pathogenic
0.47
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.81
D;D;D
Eigen
Pathogenic
0.71
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.91
.;.;D
M_CAP
Uncertain
0.21
D
MetaRNN
Pathogenic
0.96
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Benign
1.9
L;L;L
PhyloP100
7.9
PrimateAI
Uncertain
0.79
T
PROVEAN
Uncertain
-3.5
D;D;.
REVEL
Pathogenic
0.87
Sift
Benign
0.29
T;T;.
Sift4G
Benign
0.34
T;T;.
Polyphen
1.0
D;D;D
Vest4
0.93
MutPred
0.88
Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);
MVP
0.94
MPC
0.29
ClinPred
0.83
D
GERP RS
5.3
PromoterAI
0.031
Neutral
Varity_R
0.82
gMVP
0.94
Mutation Taster
=0/100
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: rs397516871; hg19: chr13-20763442; API