chr13-20188984-C-A

Variant names:

• chr13-20188984-C-A
• rs786204597
• NM_004004.6:c.598G>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_Strong PP5_Very_Strong

The NM_004004.6(GJB2):​c.598G>T​(p.Gly200*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,734 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. G200G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: GJB2 NM_004004.6 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 3.20
• Publications: 15 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: 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

ENSG00000296095 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 19 pathogenic variants in the truncated region.
• PP5: Variant 13-20188984-C-A is Pathogenic according to our data. Variant chr13-20188984-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 188973.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
GJB2	NM_004004.6	c.598G>T	p.Gly200*	stop_gained	Exon 2 of 2	ENST00000382848.5	NP_003995.2
GJB2	XM_011535049.3	c.598G>T	p.Gly200*	stop_gained	Exon 2 of 2		XP_011533351.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJB2	ENST00000382848.5	c.598G>T	p.Gly200*	stop_gained	Exon 2 of 2	1	NM_004004.6	ENSP00000372299.4
GJB2	ENST00000382844.2	c.598G>T	p.Gly200*	stop_gained	Exon 1 of 1	6		ENSP00000372295.1
ENSG00000296095	ENST00000736390.1	n.232-3404G>T		intron_variant	Intron 1 of 3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251254 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000868

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: 0.00000547 AC: 8 AN: 1461734 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727172

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000894 AC: 4 AN: 44722

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: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53326

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

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111952

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000215 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive nonsyndromic hearing loss 1A Pathogenic:2

May 06, 2021

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with both deafness and skin conditions (OMIM). Dominant negative is also a suggested mechanism (PMID: 28428247). (I) 0108 - This gene is associated with both recessive and dominant disease. The autosomal dominant diseases are commonly associated with pathogenic missense variants. The autosomal recessive disease is associated with bi-allelic loss-of-function variants and includes missense and protein truncating variants (NIH Genetics Home Reference, PMID: 12792423). (I) 0112 - The condition associated with this gene has incomplete penetrance, and is commonly reported for two specific missense (p.(Met34Thr), p.(Val37Ile)) (PMID:31160754). (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a recessive condition (4 heterozygotes, 0 homozygotes). (SP) 0600 - Variant results in the loss of part of the annotated connexin domain (NCBI). (I) 0701 - Other protein truncating variants comparable to the one identified in this case have very strong previous evidence for pathogenicity. These downstream truncating variants have been reported in individuals with autosomal recessive hearing loss (ClinVar, Decipher, PMID: 15150777, PMID: 23141775) (SP) 0803 - This variant has limited previous evidence of pathogenicity in an individual. This variant has been reported as pathogenic (LOVD, deafnessvariationdatabase) and likely pathogenic in a research setting (ClinVar), and has been observed in an individual with autosomal recessive hearing loss or congenital deafness (PMID: 15365987). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Sep 23, 2014

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

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. -

Nonsyndromic genetic hearing loss Pathogenic:1

Nov 06, 2024

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GJB2 c.598G>T (p.Gly200X) results in a premature termination codon, predicted to cause a truncation of the encoded protein, and downtream missense variants (p.Asn206Ser) has been associated disease. The variant allele was found at a frequency of 1.6e-05 in 251254 control chromosomes. c.598G>T has been reported in the literature in at-least one individual affected with Non-Syndromic Hearing Loss (example, Azaiez_2004). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 15365987). ClinVar contains an entry for this variant (Variation ID: 188973). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	38
DANN	Uncertain	0.99
Eigen	Pathogenic	0.80
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Benign	0.69	D
PhyloP100		3.2
Vest4		0.78
GERP RS		5.7
Mutation Taster		=1/199	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: rs786204597; hg19: chr13-20763123;