13-20189353-A-G

Variant names:

• chr13-20189353-A-G
• rs104894397
• NM_004004.6:c.229T>C

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PS3 PM1 PP2 PP3_Strong PP5_Very_Strong

The NM_004004.6(GJB2):​c.229T>C​(p.Trp77Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000353 in 1,614,050 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000917453: Functional studies have shown to have >99% reduction in junctional conductance in comparison to wild-type (Bruzzone_2003)." and additional evidence is available in ClinVar.

• Frequency:
  • Genomes: 𝑓 0.00011 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000027 (0 hom.)
• Consequence: GJB2 NM_004004.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:22
• Conservation: PhyloP100: 9.27
• Publications: 42 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 19 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV000917453: Functional studies have shown to have >99% reduction in junctional conductance in comparison to wild-type (Bruzzone_2003).; SCV001244781: "It is situated in the second transmembrane domain and functional studies have shown that it causes loss of channel activity." (Martin, PE. et al. (1999), Bruzzone, R. et al. (2002)); SCV002059939: The variant was previously reported to be deficient in formation of junctional channels (PMID: 18941476).; SCV007105878: "Well-established in vitro functional study supportive of damaging effect on the gene product" (PMID: 12505163); SCV000322428: Published functional studies demonstrate that the W77R variant did not form homotypic junctional channels, had impaired intercellular coupling, was inefficiently targeted to the plasma membrane, and was retained in intracellular stores (Martin et al., 1999; Bruzzone et al., 2003); SCV000958603: Experimental studies have shown that this missense change affects GJB2 function (PMID: 10556284, 12064630, 12505163).; SCV001433544: Functional studies in HeLa cells and Xenopus laevis oocytes demonstrated a deleterious effect of the mutant without dominant effect to Human CX26 by dye transfer and junctional conductance measurements assays. In both cases the levels of dye transfer and conductance did not exceed background levels (PMID: 10556284, PMID: 12064630, PMID: 12505163)
• PM1: In a hotspot region, there are 22 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 8 uncertain in NM_004004.6
• 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 dominant nonsyndromic hearing loss 3A, ichthyosis, hystrix-like, with hearing loss, autosomal recessive nonsyndromic hearing loss 1A, nonsyndromic genetic hearing loss, palmoplantar keratoderma-deafness syndrome, keratoderma hereditarium mutilans, Bart-Pumphrey syndrome, KID syndrome, autosomal dominant keratitis-ichthyosis-hearing loss syndrome, autosomal dominant nonsyndromic hearing loss, hearing loss, autosomal recessive, syndromic genetic hearing loss.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 13-20189353-A-G is Pathogenic according to our data. Variant chr13-20189353-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 17003.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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.229T>C	p.Trp77Arg	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.229T>C	p.Trp77Arg	missense	Exon 2 of 2	ENSP00000372299.4	P29033
	GJB2	ENST00000382844.2	TSL:6	c.229T>C	p.Trp77Arg	missense	Exon 1 of 1	ENSP00000372295.1	P29033
	GJB2	ENST00000906230.1		c.229T>C	p.Trp77Arg	missense	Exon 2 of 2	ENSP00000576289.1

Frequencies

GnomAD3 genomes AF: 0.000112 AC: 17 AN: 152196 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000724

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000654

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: 0.0000441

Gnomad OTH AF: 0.000478

GnomAD2 exomes AF: 0.0000398 AC: 10 AN: 251404 AF XY: 0.0000589

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000202

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000274 AC: 40 AN: 1461854 Hom.: 0 Cov.: 33 AF XY: 0.0000344 AC XY: 25 AN XY: 727224

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.000179 AC: 8 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

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

European-Non Finnish (NFE) AF: 0.0000270 AC: 30 AN: 1111998

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome AF: 0.000112 AC: 17 AN: 152196 Hom.: 0 Cov.: 32 AF XY: 0.000121 AC XY: 9 AN XY: 74354

African (AFR) AF: 0.0000724 AC: 3 AN: 41444

American (AMR) AF: 0.000654 AC: 10 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68036

Other (OTH) AF: 0.000478 AC: 1 AN: 2090

Alfa AF: 0.0000649 Hom.: 0

Bravo AF: 0.000106

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.000164

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
9	-	-	Autosomal recessive nonsyndromic hearing loss 1A (9)
6	-	-	not provided (6)
1	-	-	Autosomal dominant keratitis-ichthyosis-hearing loss syndrome;C0265964:Mutilating keratoderma;C0266004:Knuckle pads, deafness AND leukonychia syndrome;C1835672:Palmoplantar keratoderma-deafness syndrome;C1865234:Ichthyosis, hystrix-like, with hearing loss;C2673759:Autosomal recessive nonsyndromic hearing loss 1A;C2675750:Autosomal dominant nonsyndromic hearing loss 3A (1)
1	-	-	Autosomal dominant nonsyndromic hearing loss 3A (1)
1	-	-	Autosomal recessive nonsyndromic hearing loss 1A;C2675235:Autosomal recessive nonsyndromic hearing loss 1B (1)
1	-	-	GJB2-related disorder (1)
1	-	-	Hearing impairment (1)
1	-	-	Nonsyndromic genetic hearing loss (1)
1	-	-	Rare genetic deafness (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Pathogenic	3.3	M
PhyloP100		9.3
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-14	D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.96		Gain of methylation at W77 (P = 0.0122)
MVP		0.98
MPC		0.35
ClinPred		0.99	D
GERP RS		5.2
PromoterAI		0.029	Neutral
Varity_R		0.97
gMVP		0.99
Mutation Taster		=3/97	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: rs104894397; hg19: chr13-20763492;