Genetic Variant GJB2:c.-23G>A (chr13-20192783-C-T) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_004004.6(GJB2):c.-23G>A variant causes a splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000197 in 152,096 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

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

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

GJB2
NM_004004.6 splice_region

Scores

Splicing: ADA: 0.9915

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.633

Publications

8 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:

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004004.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GJB2	NM_004004.6	MANE Select	c.-23G>A		splice_region	Exon 1 of 2	NP_003995.2
	GJB2	NM_004004.6	MANE Select	c.-23G>A		5_prime_UTR	Exon 1 of 2	NP_003995.2

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein
GJB2	ENST00000382848.5	TSL:1 MANE Select	c.-23G>A	splice_region	Exon 1 of 2	ENSP00000372299.4
GJB2	ENST00000382848.5	TSL:1 MANE Select	c.-23G>A	5_prime_UTR	Exon 1 of 2	ENSP00000372299.4
ENSG00000296095	ENST00000736390.1		n.231+1672G>A	intron	N/A

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152096

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:

0.000478

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

1136

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

712

African (AFR)

AF:

0.00

AC:

AN:

American (AMR)

AF:

0.00

AC:

AN:

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

East Asian (EAS)

AF:

0.00

AC:

AN:

South Asian (SAS)

AF:

0.00

AC:

AN:

542

European-Finnish (FIN)

AF:

0.00

AC:

AN:

Middle Eastern (MID)

AF:

0.00

AC:

AN:

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

502

Other (OTH)

AF:

0.00

AC:

AN:

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152096

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74296

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41450

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5170

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10586

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67986

Other (OTH)

AF:

0.000478

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.70

CADD

Benign

(source)

DANN

Benign

0.93

PhyloP100

0.63

PromoterAI

-0.31

Neutral

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

0.99

dbscSNV1_RF

Pathogenic

0.95

SpliceAI score (max)

0.080

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over