Genetic Variant NM_004004.6:c.384C>T (chr13-20189198-G-A) – ACMG Classification: Benign (-11 pts)

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 2P and 13B. PM2BP4_StrongBP6_Very_StrongBP7

The NM_004004.6(GJB2):c.384C>T(p.Ile128Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,600 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GJB2
NM_004004.6 synonymous

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: 0.0490

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -11 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.7).

BP6

Variant 13-20189198-G-A is Benign according to our data. Variant chr13-20189198-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 44746.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr13-20189198-G-A is described in Lovd as [Likely_benign].

BP7

Synonymous conserved (PhyloP=0.049 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJB2	NM_004004.6 link	c.384C>T	p.Ile128Ile	synonymous_variant	Exon 2 of 2	ENST00000382848.5	NP_003995.2	P29033H9U1J4
GJB2	XM_011535049.3 link	c.384C>T	p.Ile128Ile	synonymous_variant	Exon 2 of 2		XP_011533351.1	P29033H9U1J4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJB2	ENST00000382848.5 link	c.384C>T	p.Ile128Ile	synonymous_variant	Exon 2 of 2	1	NM_004004.6	ENSP00000372299.4		P29033
GJB2	ENST00000382844.2 link	c.384C>T	p.Ile128Ile	synonymous_variant	Exon 1 of 1	6		ENSP00000372295.1		P29033

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461600

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727096

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

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:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:1

Feb 21, 2007

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nonsyndromic genetic hearing loss

Benign:1

Aug 31, 2020

INGEBI, INGEBI / CONICET

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on ACMG/AMP guidelines and Hearing Loss Expert Panel specific criteria: the c.384C>T p.(Ile128=) variant in GJB2 gene is absent from population databases (gnomAD, GO-ESP, 1000 genomes) meeting PM2 criteria. This variant has been detected in a heterozygous state in two hearing impaired patients (PMID:928500, 11102979). In a previous report we detected the p.Ile128= variant in cis with a pathogenic variant (PMID: 24158611). Since the cause of the hearing loss was the c.[35delG];[167delT] genotype, the p.(Ile128=) change is in cis with one of these alleles applying to BP2 rule. Computational evidence predicted that the mutation is not conserved between species (GERPscore:-1.12; BP4) and there is no impact on splicing (analyzed with Human Splicing Finder) meeting BP7 rule. Therefore, this variant meets criteria to be classified as likely benign for autosomal recessive non-syndromic hearing loss (PM2, BP2, BP4 and BP7). -

not provided

Benign:1

Jan 31, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.70

CADD

Benign

5.3

DANN

Benign

0.85

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