13-20189386-C-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM5PP2PP3_Moderate

The NM_004004.6(GJB2):c.196G>A(p.Asp66Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,556 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. D66Y) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

GJB2
NM_004004.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:4

Conservation

PhyloP100: 7.86

Publications

53 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

GJB2 links:

ENSG00000296095 (HGNC:):

ENSG00000296095 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1

In a hotspot region, there are 18 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 8 uncertain in NM_004004.6

PM5

Other missense variant is known to change same aminoacid residue: Variant chr13-20189386-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 586962.

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, 0.937

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJB2	NM_004004.6 link	c.196G>A	p.Asp66Asn	missense_variant	Exon 2 of 2	ENST00000382848.5	NP_003995.2	P29033H9U1J4
GJB2	XM_011535049.3 link	c.196G>A	p.Asp66Asn	missense_variant	Exon 2 of 2		XP_011533351.1	P29033H9U1J4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
GJB2	ENST00000382848.5 link	c.196G>A	p.Asp66Asn	missense_variant	Exon 2 of 2	1	NM_004004.6	ENSP00000372299.4	P29033
GJB2	ENST00000382844.2 link	c.196G>A	p.Asp66Asn	missense_variant	Exon 1 of 1	6		ENSP00000372295.1	P29033
ENSG00000296095	ENST00000736390.1 link	n.232-3806G>A		intron_variant	Intron 1 of 3

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152214

Hom.:

Cov.:

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:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251300

AF XY:

0.00000736

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461342

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726848

show subpopulations

African (AFR)

AF:

0.0000598

AC:

AN:

33464

American (AMR)

AF:

0.00

AC:

AN:

44708

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39688

South Asian (SAS)

AF:

0.00

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00000450

AC:

AN:

1111530

Other (OTH)

AF:

0.00

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.532

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000131

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74364

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41438

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68048

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.00000378

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1

Dec 19, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 66 of the GJB2 protein (p.Asp66Asn). This variant is present in population databases (no rsID available, gnomAD 0.004%). This missense change has been observed in individual(s) with clinical features of autosomal dominant deafness (PMID: 21055240, 24737404). ClinVar contains an entry for this variant (Variation ID: 881103). 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%. This variant disrupts the p.Asp66 amino acid residue in GJB2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10369869, 14978038, 20031451). 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. -

Ichthyosis, hystrix-like, with hearing loss

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

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 did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

not specified

Uncertain:1

Aug 23, 2023

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: GJB2 c.196G>A (p.Asp66Asn) results in a conservative amino acid change located in the Connexin, N-terminal domain (IPR013092) 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 4e-06 in 251300 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.196G>A has been reported in the literature in individuals affected with Non-Syndromic Hearing Loss (examples: Li_2010, Jiang_2014). Other variants affecting the same residue (p.Asp66His, p.Asp66Tyr) have been classified Pathogenic/likely pathogenic in ClinVar (CV IDs17012, 586962). At-least one of these variants (c.196G>C, p.Asp66His) have shown to segregate with mutilating keratoderma and deafness (Vohwinkels syndrome) in multiple families (PMIDs: 20031451, 10369869). This suggests p.Asp66 may play a critical role in normal protein function. The following publications have been ascertained in the context of this evaluation (PMID: 24737404, 21055240). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. One submitter classified the variant as likely pathogenic, and one submitter classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Autosomal recessive nonsyndromic hearing loss 1A

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

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. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Autosomal dominant nonsyndromic hearing loss 3A

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.79

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Uncertain

0.030

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.85

D;D;D

Eigen

Pathogenic

0.78

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.97

.;.;D

M_CAP

Pathogenic

0.67

MetaRNN

Pathogenic

0.94

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.3

M;M;M

PhyloP100

7.9

PrimateAI

Pathogenic

0.81

PROVEAN

Pathogenic

-5.0

D;D;.

REVEL

Pathogenic

0.83

Sift

Uncertain

0.028

D;D;.

Sift4G

Uncertain

0.025

D;D;.

Polyphen

1.0

D;D;D

Vest4

0.90

MVP

0.99

MPC

0.28

ClinPred

1.0

GERP RS

5.3

PromoterAI

0.00070

Neutral

(source)

Varity_R

0.85

gMVP

0.95

Mutation Taster

=16/84

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over