chr13-20189451-C-T

Variant names:

• chr13-20189451-C-T
• rs104894413
• NM_004004.6:c.131G>A
• GJB2 p.Trp44*

GermlineCancer (beta)

Variant summary

Our verdict is Pathogenic.

+13 Pathogenic

-7

-6

-1

0

+5

+6

+9

+10

BenignB

Likely BenignLB

UncertainVUS

Likely PathogenicLP

PathogenicP

The variant received 13 classification points (ACGS-UK Somatic Oncogenicity v2025). O1_ModerateO2_Very_StrongO3_SupportingO9_Moderate

The NM_004004.6(GJB2):c.131G>A (p.Trp44*) variant causes a stop gained change involving the alteration of a conserved nucleotide. This is a loss-of-function variant that does not trigger NMD. 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). The variant allele was found at a cumulative frequency of 0.0000062 (AC=10) in the gnomAD database across 1,613,034 control chromosomes (no homozygotes observed). The grpmax filtering allele frequency (95% CI) is 0.0000886. In-silico predictor (BayesDel (noAF)) classifies this variant as likely damaging/oncogenic. Splicing prediction tools (SpliceAI) predict no significant impact on normal splicing. The affected nucleotide is highly conserved across species (PhyloP 100-way vertebrate score: 7.85). Variant has been reported in ClinVar as Pathogenic/Likely Pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., 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:17
• Conservation: PhyloP100: 7.85
• Publications: 11 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: Pathogenic. The variant received 13 points.

Apply	Criterion Code & Title / Strength	Strength	Rationale / Clinical Context
	O1Established oncogenic variant		TSG gene: ClinVar germline P/LP ★★+ — Moderate (O1); O1 contributing sources (2.0 pts): ClinVar germline P/LP in TSG (★★)
	O2Null variant in tumour suppressor gene		Non-NMD frameshift: ≥20 downstream pathogenic — O2 very strong (+8); Use caution in the presence of multiple transcripts; Gene confirmed as TSG in CancerMine (TSG: 5 citations, oncogene: 1 citations, driver: 0 citations).; Frameshift/stop-gained. NMD predicted: false. LoF mechanism: true. Downstream pathogenic count: 213.
	O3Absent or very rare in population		Very rare in gnomAD (popmax AF <0.01%) — O3 supporting; GnomAD effective popmax AF = 0.000089 — very rare (O3 supporting [+1])
	O9Protein length change in non-repeat region		Truncating variant in final exon of oncogene — predicted GOF (O9 moderate); Truncating variant in final exon of oncogene — predicted to escape NMD and result in GOF

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.131G>A p.Trp44*	stop_gained	Exon 2 of 2	Prot: NP_003995.2

GJB2 NM_004004.6

MANE Select

HGVSc / HGVSpc.131G>Ap.Trp44*

Exon rankExon 2 of 2

stop_gained

Prot: NP_003995.2

Ensembl Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	GJB2 ENST00000382848.5	TSL:1MANE Select	c.131G>A p.Trp44*	stop_gained	Exon 2 of 2	Prot: ENSP00000372299.4 UniProt:
	GJB2 ENST00000382844.2	TSL:6	c.131G>A p.Trp44*	stop_gained	Exon 1 of 1	Prot: ENSP00000372295.1 UniProt:
	GJB2 ENST00000906230.1		c.131G>A p.Trp44*	stop_gained	Exon 2 of 2	Prot: ENSP00000576289.1 UniProt:

GJB2 ENST00000382848.5

TSL:1MANE Select

HGVSc / HGVSpc.131G>Ap.Trp44*

Exon rankExon 2 of 2

stop_gained

Prot: ENSP00000372299.4UniProt: P29033

GJB2 ENST00000382844.2

TSL:6

HGVSc / HGVSpc.131G>Ap.Trp44*

Exon rankExon 1 of 1

stop_gained

Prot: ENSP00000372295.1UniProt: P29033

GJB2 ENST00000906230.1

HGVSc / HGVSpc.131G>Ap.Trp44*

Exon rankExon 2 of 2

stop_gained

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 6 sources Large-scale international reference populations
GnomAD3 genomes	AF: 0.0000131	AC:2	Hom:0	AN:152178	Cov:33
GnomAD2 exomes	AF: 0.0000239	AC:6	Hom:	AN:250896	Cov:
GnomAD4 exome	AF: 0.00000548	AC:8	Hom:0	AN:1460856	Cov:33
GnomAD4 genome Warning	AF: 0.0000131	AC:2	Hom:0	AN:152178	Cov:33
TOPMed (Bravo)	AF: 0.0000151	AC:	Hom:	AN:	Cov:
ALFA (dbGaP/dbSNP Allele Frequency Aggregator)	AF: 0.00	AC:0	Hom:0	AN:13470	Cov:

Showing 6 sources

Case/control cohorts

Cohort	Cases			Controls
	AF	AC	AN	AF	AC	AN
SCHEMA(Schizophrenia)	0.0000194	2	103184	0.00000543	1	184256

Showing 1 cohortAllele count / allele number. AF is computed from the counts for ASC (not provided by the source).

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
8	-	-	Autosomal recessive nonsyndromic hearing loss 1A (8)
5	-	-	not provided (5)
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	-	-	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	-	-	GJB2-related disorder (1)
1	-	-	Inborn genetic diseases (1)

Computational Scores

Algorithm	Calibrated pred.	Score	Prediction
AlphaGenome AVI	Pathogenic	39
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	42
DANN	Uncertain	1.0
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Uncertain	0.97	D
GPN-Star LLR	N/A	-8.6
GPN-Star score	N/A	8.6
Mutation Taster	N/A	1/199	disease causing (ClinVar)
PhyloP100	Pathogenic	7.9
PromoterAI	N/A	-0.026	Neutral

Showing 13 of 13 scores

Splicing Scores

Algorithm	Calibrated pred.	Score	Prediction
Pangolin (max)	Benign	0.0
SpliceAI score (max)	Benign	0.0	Details are displayed if max score is > 0.2

Showing 2 of 2 scores

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

dbSNP: rs104894413;

hg19: chr13-20763590;

ACMG debug oncogenicity

ACGS debug oncogenicity

ACMG debug germline

Submit to ClinVar