rs1555936989

Variant names:

• chrX-71223715-G-A
• rs1555936989
• NM_000166.6:c.8G>A

Your query was ambiguous. Multiple possible variants found:

• chrX-71223715-G-A
• chrX-71223715-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_000166.6(GJB1):​c.8G>A​(p.Trp3*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: GJB1 NM_000166.6 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1 U:2
• Conservation: PhyloP100: 9.97

Genes affected

GJB1 (HGNC:4283): (gap junction protein beta 1) This gene encodes a member of the gap junction protein family. The gap junction proteins are membrane-spanning proteins that assemble to form gap junction channels that facilitate the transfer of ions and small molecules between cells. 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 cause X-linked Charcot-Marie-Tooth disease, an inherited peripheral neuropathy. Alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-71223715-G-A is Pathogenic according to our data. Variant chrX-71223715-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 543927.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chrX-71223715-G-A is described in Lovd as [Pathogenic]. Variant chrX-71223715-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJB1	NM_000166.6	c.8G>A	p.Trp3*	stop_gained	Exon 2 of 2	ENST00000361726.7	NP_000157.1
GJB1	NM_001097642.3	c.8G>A	p.Trp3*	stop_gained	Exon 2 of 2		NP_001091111.1
GJB1	XM_011530907.3	c.8G>A	p.Trp3*	stop_gained	Exon 2 of 2		XP_011529209.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJB1	ENST00000361726.7	c.8G>A	p.Trp3*	stop_gained	Exon 2 of 2	1	NM_000166.6	ENSP00000354900.6

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth Neuropathy X Pathogenic:1

Sep 20, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Several truncations downstream of this variant (p.Tyr65* and p.Arg220*) have been determined to be pathogenic (PMID: 224645664, 7477983, 9364054). This suggests that deletion of this region of the GJB1 protein is causative of disease. This sequence change results in a premature translational stop signal in the GJB1 gene (p.Trp3*). While this is not anticipated to result in nonsense mediated decay, it is expected to delete the last 281 amino acids (99%) of the GJB1 protein. This variant is not present in population databases (ExAC no frequency). This variant has been reported in several individuals affected with Charcot-Marie-Tooth disease, type X1 (PMID: 22464564, 27088055, 27804109). -

Charcot-Marie-Tooth disease Uncertain:1

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Inherited Neuropathy Consortium

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Charcot-Marie-Tooth disease X-linked dominant 1 Uncertain:1

Jan 06, 2016

Inherited Neuropathy Consortium Ii, University Of Miami

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	37
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.97	D
Vest4		0.72
GERP RS		4.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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

Other links and lift over

dbSNP: rs1555936989; hg19: chrX-70443565;