NM_004004.6:c.120A>C

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_StrongBP6BP7

The NM_004004.6(GJB2):​c.120A>C​(p.Ala40Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000157 in 1,613,546 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. A40A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00016 ( 0 hom. )

Consequence

GJB2
NM_004004.6 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:8

Conservation

PhyloP100: -9.42

Publications

2 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: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-1.02).
BP6
Variant 13-20189462-T-G is Benign according to our data. Variant chr13-20189462-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 195206.
BP7
Synonymous conserved (PhyloP=-9.42 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GJB2NM_004004.6 linkc.120A>C p.Ala40Ala synonymous_variant Exon 2 of 2 ENST00000382848.5 NP_003995.2 P29033H9U1J4
GJB2XM_011535049.3 linkc.120A>C p.Ala40Ala synonymous_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.120A>C p.Ala40Ala synonymous_variant Exon 2 of 2 1 NM_004004.6 ENSP00000372299.4 P29033
GJB2ENST00000382844.2 linkc.120A>C p.Ala40Ala synonymous_variant Exon 1 of 1 6 ENSP00000372295.1 P29033
ENSG00000296095ENST00000736390.1 linkn.232-3882A>C intron_variant Intron 1 of 3

Frequencies

GnomAD3 genomes
AF:
0.000145
AC:
22
AN:
152204
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:
0.000323
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000171
AC:
43
AN:
250886
AF XY:
0.000221
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:
0.000231
Gnomad NFE exome
AF:
0.000300
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.000158
AC:
231
AN:
1461224
Hom.:
0
Cov.:
33
AF XY:
0.000172
AC XY:
125
AN XY:
726782
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39680
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86244
European-Finnish (FIN)
AF:
0.000150
AC:
8
AN:
53410
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5766
European-Non Finnish (NFE)
AF:
0.000193
AC:
215
AN:
1111436
Other (OTH)
AF:
0.0000663
AC:
4
AN:
60372
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
13
26
40
53
66
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:
0.000144
AC:
22
AN:
152322
Hom.:
0
Cov.:
33
AF XY:
0.000121
AC XY:
9
AN XY:
74482
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41570
American (AMR)
AF:
0.00
AC:
0
AN:
15308
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000323
AC:
22
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.484
Heterozygous variant carriers
0
2
4
6
8
10
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:
0.000225
Hom.:
0
Bravo
AF:
0.000136
EpiCase
AF:
0.000273
EpiControl
AF:
0.000474

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:8
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Benign:3
Feb 16, 2025
Laboratory of Genetics, Children's Clinical University Hospital Latvia
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 28, 2019
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 24, 2018
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1Benign:1
Jan 15, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 10, 2014
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive nonsyndromic hearing loss 1A Benign:2
Feb 22, 2020
Natera, Inc.
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Ichthyosis, hystrix-like, with hearing loss Benign:1
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Autosomal dominant nonsyndromic hearing loss 3A Benign:1
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-1.0
CADD
Benign
0.013
DANN
Benign
0.53
PhyloP100
-9.4
PromoterAI
0.071
Neutral
Mutation Taster
=100/0
polymorphism

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: rs561870637; hg19: chr13-20763601; API