1-34784955-TACG-T

Position:

chr1-34784955-TACG-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM1PM4_SupportingBS2

The NM_024009.3(GJB3):c.196_198del(p.Asp66del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000898 in 1,614,192 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00017 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000081 ( 0 hom. )

Consequence

GJB3
NM_024009.3 inframe_deletion

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:6

Conservation

PhyloP100: 9.94

Variant links:

Genes affected

GJB3 (HGNC:4285): (gap junction protein beta 3) This gene is a member of the connexin gene family. The encoded protein is a component of gap junctions, which are composed of arrays of intercellular channels that provide a route for the diffusion of low molecular weight materials from cell to cell. Mutations in this gene can cause non-syndromic deafness or erythrokeratodermia variabilis, a skin disorder. Alternative splicing results in multiple transcript variants encoding the same protein. [provided by RefSeq, Jul 2008]

GJB3 links:

SMIM12 (HGNC:25154): (small integral membrane protein 12) Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

SMIM12 links:

(HGNC:):

links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM1

In a chain Gap junction beta-3 protein (size 269) in uniprot entity CXB3_HUMAN there are 17 pathogenic changes around while only 4 benign (81%) in NM_024009.3

PM4

Nonframeshift variant in NON repetitive region in NM_024009.3. Strenght limited to Supporting due to length of the change: 1aa.

BS2

High AC in GnomAd4 at 26 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GJB3	NM_024009.3 linkuse as main transcript	c.196_198del	p.Asp66del	inframe_deletion	2/2	ENST00000373366.3	NP_076872.1
GJB3	NM_001005752.2 linkuse as main transcript	c.196_198del	p.Asp66del	inframe_deletion	2/2		NP_001005752.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris
GJB3	ENST00000373366.3 linkuse as main transcript	c.196_198del	p.Asp66del	inframe_deletion	2/2	1	NM_024009.3	ENSP00000362464	P1
GJB3	ENST00000373362.3 linkuse as main transcript	c.196_198del	p.Asp66del	inframe_deletion	2/2	1		ENSP00000362460	P1
SMIM12	ENST00000426886.1 linkuse as main transcript	c.208-66549_208-66547del		intron_variant, NMD_transcript_variant		1		ENSP00000429902
	ENST00000542839.1 linkuse as main transcript	n.110+3030_110+3032del		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes

AF:

0.000171

AC:

AN:

152184

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000314

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000327

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:

0.000118

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000139

AC:

AN:

251390

Hom.:

AF XY:

0.0000809

AC XY:

AN XY:

135892

show subpopulations

Gnomad AFR exome

AF:

0.000308

Gnomad AMR exome

AF:

0.000405

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000123

Gnomad OTH exome

AF:

0.000326

GnomAD4 exome

AF:

0.0000814

AC:

119

AN:

1461890

Hom.:

AF XY:

0.0000633

AC XY:

AN XY:

727248

show subpopulations

Gnomad4 AFR exome

AF:

0.000149

Gnomad4 AMR exome

AF:

0.000358

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000773

Gnomad4 OTH exome

AF:

0.000166

GnomAD4 genome

AF:

0.000171

AC:

AN:

152302

Hom.:

Cov.:

AF XY:

0.000121

AC XY:

AN XY:

74464

show subpopulations

Gnomad4 AFR

AF:

0.000313

Gnomad4 AMR

AF:

0.000327

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000118

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000217

Hom.:

Bravo

AF:

0.000193

EpiCase

AF:

0.000164

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:6

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1Uncertain:4

Uncertain significance, criteria provided, single submitter	clinical testing	Athena Diagnostics	Mar 14, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Mar 22, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jan 01, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 10, 2024	In-frame deletion of 1 amino acid in a non-repeat region; In silico analysis supports a deleterious effect on protein structure/function; Published in vitro expression studies suggest a damaging effect; a portion of the mutant protein does not reach the cell membrane suggestive of an intracellular trafficking defect and cells shows altered gap junction function, while there was no evidence for an increased rate of cell death in contrast to GJB3 variants associated with skin disorders (PMID: 12165562, 19755382); This variant is associated with the following publications: (PMID: 19755382, 11179004, 12165562, 11758118, 12823303, 29044474, 19197336, 35580552, 36515421, 36147510, 11309368) -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 01, 2024	This variant, c.196_198del, results in the deletion of 1 amino acid(s) of the GJB3 protein (p.Asp66del), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs777106179, gnomAD 0.04%). This variant has been observed in individual(s) with hearing impairment and/or neuropathy (PMID: 11309368, 35580552). ClinVar contains an entry for this variant (Variation ID: 6490). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this variant affects GJB3 function (PMID: 12165562). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Deafness, autosomal dominant, with peripheral neuropathy

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Apr 15, 2001

- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Nov 20, 2022

Variant summary: GJB3 c.196_198delGAC (p.Asp66del) results in an in-frame deletion that is predicted to remove one amino acid from the encoded protein. The variant allele was found at a frequency of 0.00014 in 251390 control chromosomes. This frequency does not allow conclusions about variant significance. c.196_198delGAC has been reported in the literature as a dominant mutation in at-least one family with sensorineural hearing loss and peripheral neuropathy (5 genotyped affected transmissions) where it showed both non-segregation (one reference allele transmission to a genotyped affected) and variable penetrance (an unaffected individual with the variant) (example, Lopez-Bigas_2001).These data indicate that the variant may be associated with disease although the authors suggest that other genetic modifiers or environmental factors could contribute to the overall phenotypic spectrum of manifesations. At least two publications report experimental evidence evaluating an impact on protein function evaluating defective channel formation by localization studies and dye transfer experiments, however, do not allow convincing conclusions about the variant effect (example, Di_2002, Tattersall_2009). Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (VUS, n=5; Pathogenic, n=1). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Hearing impairment

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Jun 23, 2021

ACMG classification criteria: PS3 supporting, PM4 moderate, BS1 strong -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over