13-20189332-C-G

Variant names:

• chr13-20189332-C-G
• rs104894409
• NM_004004.6:c.250G>C

Variant summary

Our verdict is Pathogenic. The variant received 29 ACMG points: 29P and 0B. PS1_Very_Strong PS3 PM1 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_004004.6(GJB2):​c.250G>C​(p.Val84Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000335 in 1,461,806 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 (★★). ClinVar reports functional evidence for this variant: "SCV000698239: Multiple functional studies show that although the V84L mutant channels are able to make gap junctions in mammalian and insect cells, stable in detergent solution and able to allow passage of simple ions (such as LY), they do not allow permeability for molecules larger than simple ions (such as propidium iodide) and reduce permeability to the Ca2+-mobilizing messenger inositol 1,4,5-trisphosphate (Bruzzone_2003, Wang_2003, Beltramello_2005, Zhang_2005, Ambrosi_2010)." and additional evidence is available in ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V84M) has been classified as Pathogenic. The gene GJB2 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000034 (0 hom.)
• Consequence: GJB2 NM_004004.6 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:17
• Conservation: PhyloP100: 7.86
• Publications: 65 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

Specifications for GJB2 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 29 ACMG points.

• PS1: Transcript NM_004004.6 (GJB2) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000698239: Multiple functional studies show that although the V84L mutant channels are able to make gap junctions in mammalian and insect cells, stable in detergent solution and able to allow passage of simple ions (such as LY), they do not allow permeability for molecules larger than simple ions (such as propidium iodide) and reduce permeability to the Ca2+-mobilizing messenger inositol 1,4,5-trisphosphate (Bruzzone_2003, Wang_2003, Beltramello_2005, Zhang_2005, Ambrosi_2010).; SCV000061492: Functional studies indicate that the Val84Leu variant compromises connexin 26 protein function (Beltramello 2005).; SCV001205435: Experimental studies have shown that this missense change affects GJB2 function (PMID: 12505163, 12562518, 15592461, 16217030, 20441744).; SCV001476374: Studies show this variant results in impaired permeability to larger molecules, such as inositol 1,4,5-trisphosphate (PMID: 15592461, 16217030).; SCV001770240: Published functional studies demonstrate a damaging effect on biochemical permeability, while ionic coupling is intact (PMID: 16217030); SCV004046406: Functional studies have shown that this missense change affects biochemical permeability and intercellular transport of large molecules (PMID: 12505163, 12562518, 15592461, 20441744, 16217030).
• PM1: In a hotspot region, there are 18 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 11 uncertain in NM_004004.6
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr13-20189332-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 17036.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• 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, 0.94
• PP5: Variant 13-20189332-C-G is Pathogenic according to our data. Variant chr13-20189332-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 17032.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.250G>C	p.Val84Leu	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.250G>C	p.Val84Leu	missense	Exon 2 of 2	ENSP00000372299.4	P29033
	GJB2	ENST00000382844.2	TSL:6	c.250G>C	p.Val84Leu	missense	Exon 1 of 1	ENSP00000372295.1	P29033
	GJB2	ENST00000906230.1		c.250G>C	p.Val84Leu	missense	Exon 2 of 2	ENSP00000576289.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000358 AC: 9 AN: 251338 AF XY: 0.0000442

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.000116

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000352

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000335 AC: 49 AN: 1461806 Hom.: 0 Cov.: 33 AF XY: 0.0000385 AC XY: 28 AN XY: 727212

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

American (AMR) AF: 0.0000447 AC: 2 AN: 44722

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: 53350

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

European-Non Finnish (NFE) AF: 0.0000387 AC: 43 AN: 1112008

Other (OTH) AF: 0.0000662 AC: 4 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000227

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.0000659 AC: 8

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
8	-	-	Autosomal recessive nonsyndromic hearing loss 1A (8)
4	-	-	not provided (4)
1	-	-	Autosomal dominant keratitis-ichthyosis-hearing loss syndrome;C0265964:Mutilating keratoderma;C0266004:Knuckle pads, deafness AND leukonychia syndrome;C1835672:Palmoplantar keratoderma-deafness syndrome;C1844678:X-linked mixed hearing loss with perilymphatic gusher;C1865234:Ichthyosis, hystrix-like, with hearing loss;C2673759:Autosomal recessive nonsyndromic hearing loss 1A;C2675750:Autosomal dominant nonsyndromic hearing loss 3A (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	0.93
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.54
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.8	M
PhyloP100		7.9
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.0	D
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.98		Loss of glycosylation at S85 (P = 0.0994)
MVP		0.98
MPC		0.28
ClinPred		0.88	D
GERP RS		5.3
PromoterAI		0.087	Neutral
Varity_R		0.90
gMVP		0.96
Mutation Taster		=2/98	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: rs104894409; hg19: chr13-20763471;