NM_004004.6:c.56G>C

Variant names:

• chr13-20189526-C-G
• rs80338941
• NM_004004.6:c.56G>C

Variant summary

Our verdict is Pathogenic. The variant received 6 ACMG points: 6P and 0B. PP1 PM2_Supporting PM3 PS3_Moderate

This summary comes from the ClinGen Evidence Repository: The variant NM_004004.6:c.56G>C in GJB2 is a missense variant predicted to cause substitution of serine by threonine at amino acid 19 (p.Ser19Thr). The highest filtering allele frequency in gnomAD v4 is 0.00111% (19/1111946 CI 95%) in the non-Finnish European population (PM2_Supporting). This variant has been detected in 5 probands with hearing loss. For 4 of those probands, a pathogenic or suspected-pathogenic variants was observed in trans (PM3_VeryStrong; PMIDs: 16077952, 26553399, 10982180, 15146474, Partners Laboratory for Molecular Medicine internal data). Of note, 1 proband was compound-heterozygous for Ser19Thr with c.35delG and also carried Arg32Ser in cis; another proband had Ser19Thr, Arg32Ser and E47* in unspecified zygosity though it is assumed that Ser19Thr and Arg32Ser were in cis based on prior observation. These cases were not counted towards PM3 because contribution of the Arg32Ser variant can not be ruled out. The p.Ser19Thr variant has been reported to segregate with hearing loss in one affected family member (PP1, PMID:16077952). A functional study has shown that p.Ser19Thr impacts protein function (PS3_Moderate; PMID:12176036). In summary, this variant meets the criteria to be classified as pathogenic for autosomal recessive nonsyndromic sensorineural hearing loss, based on the ACMG/AMP criteria applied, as specified by the ClinGen Hearing Loss VCEP: PM3_VeryStrong, PS3_Moderate, PM2_Supporting, PP1 (ClinGen Hearing Loss VCEP specifications version 2; 1/3/24). LINK:https://erepo.genome.network/evrepo/ui/classification/CA342005/MONDO:0019497/005

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000015 (0 hom.)
• Consequence: GJB2 NM_004004.6 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:8 U:1 O:1
• Conservation: PhyloP100: 3.30
• Publications: 10 publications found

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: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• 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, G2P, Genomics England PanelApp
• palmoplantar keratoderma-deafness syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, G2P
• syndromic genetic hearing loss

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• autosomal recessive nonsyndromic hearing loss 1A

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine
• nonsyndromic genetic hearing loss

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• autosomal dominant keratitis-ichthyosis-hearing loss syndrome

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp
• autosomal dominant nonsyndromic hearing loss 3A

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• autosomal dominant nonsyndromic hearing loss

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• KID syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000296095 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 6 ACMG points.

• PS3: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GJB2	NM_004004.6	MANE Select	c.56G>C	p.Ser19Thr	missense	Exon 2 of 2	NP_003995.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GJB2	ENST00000382848.5	TSL:1 MANE Select	c.56G>C	p.Ser19Thr	missense	Exon 2 of 2	ENSP00000372299.4	P29033
	GJB2	ENST00000382844.2	TSL:6	c.56G>C	p.Ser19Thr	missense	Exon 1 of 1	ENSP00000372295.1	P29033
	GJB2	ENST00000906230.1		c.56G>C	p.Ser19Thr	missense	Exon 2 of 2	ENSP00000576289.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000120 AC: 3 AN: 249778 AF XY: 0.0000148

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: 0.0000268

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000150 AC: 22 AN: 1461822 Hom.: 0 Cov.: 32 AF XY: 0.0000165 AC XY: 12 AN XY: 727214

African (AFR) AF: 0.00 AC: 0 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: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000171 AC: 19 AN: 1111946

Other (OTH) AF: 0.0000497 AC: 3 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000312 Hom.: 0

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.000109

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
3	-	-	not provided (3)
1	1	-	Autosomal recessive nonsyndromic hearing loss 1A (3)
2	-	-	Nonsyndromic genetic hearing loss (2)
1	-	-	Hearing loss (1)
1	-	-	Rare genetic deafness (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.090
CADD	Uncertain	23
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.76	D
Eigen	Uncertain	0.26
Eigen_PC	Uncertain	0.34
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.52	T
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.2	M
PhyloP100		3.3
PrimateAI	Uncertain	0.68	T
PROVEAN	Benign	-1.6	N
REVEL	Uncertain	0.63
Sift	Benign	0.31	T
Sift4G	Benign	0.062	T
Polyphen		0.46	P
Vest4		0.43
MutPred		0.83		Gain of ubiquitination at K22 (P = 0.0817)
MVP		0.94
MPC		0.14
ClinPred		0.47	T
GERP RS		5.2
PromoterAI		0.021	Neutral
Varity_R		0.68
gMVP		0.85
Mutation Taster		=8/92	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

Other links and lift over

dbSNP: rs80338941; hg19: chr13-20763665; COSMIC: COSV67010547; COSMIC: COSV67010547;