rs199834862

Positions:

chrX-71224363-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 5P and 4B. PM1PM5PP3BS2

The ENST00000361726.7(GJB1):c.656G>A(p.Arg219His) variant causes a missense change. The variant allele was found at a frequency of 0.00000663 in 1,206,933 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 2 hemizygotes in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R219C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000018 ( 0 hom., 0 hem., cov: 22)

Exomes 𝑓: 0.0000055 ( 0 hom. 2 hem. )

Consequence

GJB1
ENST00000361726.7 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:3

Conservation

PhyloP100: 3.75

Variant links:

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]

GJB1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 8 uncertain in ENST00000361726.7

PM5

Other missense variant is known to change same aminoacid residue: Variant chrX-71224362-C-T is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.766

BS2

High Hemizygotes in GnomAdExome4 at 2 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
GJB1	NM_000166.6 linkuse as main transcript	c.656G>A	p.Arg219His	missense_variant	2/2	ENST00000361726.7	NP_000157.1
GJB1	NM_001097642.3 linkuse as main transcript	c.656G>A	p.Arg219His	missense_variant	2/2		NP_001091111.1
GJB1	XM_011530907.3 linkuse as main transcript	c.656G>A	p.Arg219His	missense_variant	2/2		XP_011529209.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GJB1	ENST00000361726.7 linkuse as main transcript	c.656G>A	p.Arg219His	missense_variant	2/2	1	NM_000166.6	ENSP00000354900	P1

Frequencies

GnomAD3 genomes

AF:

0.0000181

AC:

AN:

110313

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

32615

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000287

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000189

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000554

AC:

AN:

180621

Hom.:

AF XY:

0.00

AC XY:

AN XY:

65553

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000724

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1096565

Hom.:

Cov.:

AF XY:

0.00000552

AC XY:

AN XY:

362215

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000331

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000594

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000181

AC:

AN:

110368

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

32678

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000288

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000189

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease

Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Uncertain significance, no assertion criteria provided	literature only	Inherited Neuropathy Consortium	-	- -

Charcot-Marie-Tooth Neuropathy X

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 02, 2021

This sequence change replaces arginine with histidine at codon 219 of the GJB1 protein (p.Arg219His). The arginine residue is highly conserved and there is a small physicochemical difference between arginine and histidine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with Charcot-Marie-Tooth disease (PMID: 9361298). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). Experimental studies have shown that this missense change does not substantially affect GJB1 function (PMID: 12460545, 21280457). 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Pathogenic

0.37

BayesDel_noAF

Pathogenic

0.30

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.38

T;T;T;T;T

FATHMM_MKL

Uncertain

0.97

LIST_S2

Benign

0.82

.;.;.;.;T

M_CAP

Pathogenic

0.95

MetaRNN

Pathogenic

0.77

D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Benign

1.0

L;L;L;L;L

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.58

PROVEAN

Benign

-1.8

N;.;N;.;N

REVEL

Pathogenic

0.79

Sift

Benign

0.097

T;.;T;.;T

Sift4G

Benign

0.11

T;.;T;.;T

Polyphen

1.0

D;D;D;D;D

Vest4

0.14

MVP

0.99

MPC

1.6

ClinPred

0.86

GERP RS

4.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.27

gMVP

0.95

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