13-20189297-CAC-GAG

Variant names:

• chr13-20189297-CAC-GAG
• NM_004004.6:c.283_285delGTGinsCTC
• GJB2 p.Val95Leu

GermlineCancer (beta)

Variant summary

Our verdict is Uncertain significance.

+5 Uncertain · Hot

-7

-6

-1

0

+5

+6

+9

+10

BenignB

Likely BenignLB

UncertainVUS

Likely PathogenicLP

PathogenicP

The variant received 5 classification points (ACGS-UK Somatic Oncogenicity v2025). O3_ModerateO5_SupportingO7_SupportingO8_Supporting

The NM_004004.6(GJB2):c.283_285delGTGinsCTC (p.Val95Leu) variant causes a missense change. The gene GJB2 is a tumor suppressor gene (CancerMine: 5 TSG, 1 oncogene citations). The gene GJB2 is a known oncogene (CancerMine: 5 TSG, 1 oncogene citations). Note: allele frequency estimates from gnomAD may be inaccurate for this variant type (MNP or indel longer than 3 bp) due to technology limitations. The variant is absent from the gnomAD population database at sites with sufficient sequencing coverage. The affected nucleotide is highly conserved across species (PhyloP 100-way vertebrate score: 9.27). No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. A different missense at the same amino acid position has been reported as Pathogenic/Likely Pathogenic in ClinVar: p.V95M: Pathogenic/Likely_pathogenic (ClinVar VariationId 44735, 2 stars) Other variants at the same amino acid position have been reported in ClinVar (not pathogenic): p.V95L: VUS-low (ClinVar VariationId 4856990, 1 star)

• Frequency: Genomes: not found (cov: 32)
• Consequence: GJB2 NM_004004.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.27
• Publications: 0 publications found

Genes affected

GJB2 (HGNC:4284): (gap junction protein beta 2) This gene encodes a member of the gap junction protein family (gap junction beta 2) but is more commonly known as connexin 26. 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. Connexins form hexameric channels in the plasma membrane which regulate passage of ions and small molecules between the cell and its environment or, when joined with another cell, form a dodecameric intercellular gap junction channel. The connexin proteins are grouped into alpha, beta, and gamma subfamilies. Mutations in this gene are responsible for as much as 50% of pre-lingual, recessive deafness. [provided by RefSeq, Mar 2026]

GJB2 Gene-Disease associations (from GenCC):

• Bart-Pumphrey syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
• hearing loss disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• ichthyosis, hystrix-like, with hearing loss

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P
• keratoderma hereditarium mutilans

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
• palmoplantar keratoderma-deafness syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
• autosomal recessive nonsyndromic hearing loss 1A

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, G2P, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae)
• 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: Genomics England PanelApp, Ambry Genetics, PanelApp Australia
• autosomal dominant nonsyndromic hearing loss 3A

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), PanelApp Australia
• 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:):

Classification according to ACGS-UK Somatic Oncogenicity v2025

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

Classification was made for transcript:

Our verdict: Uncertain_significance. The variant received 5 points.

Apply	Criterion Code & Title / Strength	Strength	Rationale / Clinical Context
	O3Absent or very rare in population		Absent or extremely rare in gnomAD (AC ≤ 2) — O3 moderate; GnomAD: AF = absent, AC = 0 — absent/extremely rare (O3 moderate [+2])
	O5Same location/impact as known oncogenic		Different AA at same residue with oncogenic evidence (or germline P/LP in TSG), or same AA change SCI Tier II Potential — Supporting (O5); ClinVar same-AA oncogenic/T1: false | ClinVar same-AA SCI tier: — | CGI same-AA oncogenic: false | TSG: true | ClinVar same-AA germline P/LP: false | CIViC LOF: false | ClinVar diff-AA oncogenic: false | ClinVar diff-AA germline P/LP: true
	O7Mutational hotspot or critical domain		Supporting: cancerhotspots.org hit, critical domain, or missense neighbourhood hotspot; No cancerhotspots.org hit at this position; UniProt domain: 0 pathogenic, 0 benign.; ±8 AA neighbourhood: 11 pathogenic, 0 benign (OR vs. background: 115.0); Variant does not impact splicing — splice-hotspot path not applicable
	O8Missense constraint in gene or region		Missense in gene/domain constrained for missense variation where missense is common disease mechanism (O8 supporting); Gene/disease mechanism: missense is a common mechanism of oncogenesis; gnomAD missense Z-score: 0.44 (threshold ≥3.09 for constraint); Domain-level constraint: variant is in a critically constrained functional domain (IS_AT_CRITICAL_DOMAIN)

Variant Effect in Transcripts

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

RefSeq Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	GJB2 NM_004004.6	MANE Select	c.283_285delGTGinsCTC p.Val95Leu	missense	N/A	Prot: NP_003995.2

GJB2 NM_004004.6

MANE Select

HGVSc / HGVSpc.283_285delGTGinsCTCp.Val95Leu

Exon rankN/A

missense

Prot: NP_003995.2

Ensembl Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	GJB2 ENST00000382848.5	TSL:1MANE Select	c.283_285delGTGinsCTC p.Val95Leu	missense	N/A	Prot: ENSP00000372299.4 UniProt:
	GJB2 ENST00000382844.2	TSL:6	c.283_285delGTGinsCTC p.Val95Leu	missense	N/A	Prot: ENSP00000372295.1 UniProt:
	GJB2 ENST00000906230.1		c.283_285delGTGinsCTC p.Val95Leu	missense	N/A	Prot: ENSP00000576289.1 UniProt:

GJB2 ENST00000382848.5

TSL:1MANE Select

HGVSc / HGVSpc.283_285delGTGinsCTCp.Val95Leu

Exon rankN/A

missense

Prot: ENSP00000372299.4UniProt: P29033

GJB2 ENST00000382844.2

TSL:6

HGVSc / HGVSpc.283_285delGTGinsCTCp.Val95Leu

Exon rankN/A

missense

Prot: ENSP00000372295.1UniProt: P29033

GJB2 ENST00000906230.1

HGVSc / HGVSpc.283_285delGTGinsCTCp.Val95Leu

Exon rankN/A

missense

Prot: ENSP00000576289.1UniProt: P29033

Frequencies

Allele frequencies (AF), counts (AC/AN), homozygotes and coverage

Common (AF > 0.05 / Hom > 5)

Rare (AF ≤ 0.0001 / Hom ≤ 1)

Source / population	AF	AC	Hom	AN	Coverage
Global population databases 2 sources Large-scale international reference populations
GnomAD3 genomes	AF:	AC:	Hom:	AN:	Cov:32
GnomAD4 genome	AF:	AC:	Hom:	AN:	Cov:32

Showing 2 sources

Tested, but no data found:GnomAD4 exomeIf GnomAD4 is missing, the position is probably not covered by the project.

ClinVar

Not reported in ClinVar

Computational Scores

Algorithm	Calibrated pred.	Score	Prediction
PhyloP100	Pathogenic	9.3

Showing 1 of 1 scores

Splicing Scores

No splicing scores have been computed for this variant.

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

MaveDB functional evidence

MaveDB is a public repository of laboratory assays that test the effect of thousands of variants at once — treat this as supporting research data and interpret it with great caution; it is not a clinical classification.

No MaveDB functional evidence found for this variant.

Other links and lift over

hg19: chr13-20763436;

ACMG debug oncogenicity

ACGS debug oncogenicity

ACMG debug germline

Submit to ClinVar