chrX-71224419-C-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 3P and 6B. PM1PP2BP4_ModerateBS2

The NM_000166.6(GJB1):​c.712C>T​(p.Arg238Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000116 in 1,208,174 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 5 hemizygotes in GnomAD. In-silico tool predicts a benign 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. R238L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000090 ( 0 hom., 0 hem., cov: 22)
Exomes 𝑓: 0.000012 ( 0 hom. 5 hem. )

Consequence

GJB1
NM_000166.6 missense

Scores

1
10
6

Clinical Significance

Uncertain significance criteria provided, single submitter U:3

Conservation

PhyloP100: 1.10

Publications

3 publications found
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 Gene-Disease associations (from GenCC):
  • Charcot-Marie-Tooth disease X-linked dominant 1
    Inheritance: XL Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, PanelApp Australia, ClinGen, Labcorp Genetics (formerly Invitae)
  • X-linked progressive cerebellar ataxia
    Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PM1
In a chain Gap junction beta-1 protein (size 282) in uniprot entity CXB1_HUMAN there are 184 pathogenic changes around while only 11 benign (94%) in NM_000166.6
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 135 curated pathogenic missense variants (we use a threshold of 10). The gene has 4 curated benign missense variants. Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to Charcot-Marie-Tooth disease X-linked dominant 1, X-linked progressive cerebellar ataxia.
BP4
Computational evidence support a benign effect (MetaRNN=0.22363439).
BS2
High Hemizygotes in GnomAdExome4 at 5 XL gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GJB1NM_000166.6 linkc.712C>T p.Arg238Cys missense_variant Exon 2 of 2 ENST00000361726.7 NP_000157.1 P08034A0A654ICJ7
GJB1NM_001097642.3 linkc.712C>T p.Arg238Cys missense_variant Exon 2 of 2 NP_001091111.1 P08034A0A654ICJ7
GJB1NM_001440770.1 linkc.712C>T p.Arg238Cys missense_variant Exon 3 of 3 NP_001427699.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GJB1ENST00000361726.7 linkc.712C>T p.Arg238Cys missense_variant Exon 2 of 2 1 NM_000166.6 ENSP00000354900.6 P08034

Frequencies

GnomAD3 genomes
AF:
0.00000897
AC:
1
AN:
111500
Hom.:
0
Cov.:
22
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000166
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000451
AC:
8
AN:
177357
AF XY:
0.0000476
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000136
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000467
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000119
AC:
13
AN:
1096619
Hom.:
0
Cov.:
32
AF XY:
0.0000138
AC XY:
5
AN XY:
362117
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
26380
American (AMR)
AF:
0.00
AC:
0
AN:
35120
Ashkenazi Jewish (ASJ)
AF:
0.0000517
AC:
1
AN:
19354
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30167
South Asian (SAS)
AF:
0.00
AC:
0
AN:
53851
European-Finnish (FIN)
AF:
0.000274
AC:
11
AN:
40089
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4137
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
841479
Other (OTH)
AF:
0.0000217
AC:
1
AN:
46042
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000896
AC:
1
AN:
111555
Hom.:
0
Cov.:
22
AF XY:
0.00
AC XY:
0
AN XY:
33741
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
30696
American (AMR)
AF:
0.00
AC:
0
AN:
10532
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2642
East Asian (EAS)
AF:
0.00
AC:
0
AN:
3523
South Asian (SAS)
AF:
0.00
AC:
0
AN:
2647
European-Finnish (FIN)
AF:
0.000166
AC:
1
AN:
6036
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
216
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
53060
Other (OTH)
AF:
0.00
AC:
0
AN:
1518
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000544
Hom.:
1
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease Uncertain:2
-
Inherited Neuropathy Consortium
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Dec 07, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Charcot-Marie-Tooth Neuropathy X Uncertain:1
Jun 28, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine with cysteine at codon 238 of the GJB1 protein (p.Arg238Cys). The arginine residue is moderately conserved and there is a large physicochemical difference between arginine and cysteine. This variant is present in population databases (rs200774406, ExAC 0.03%). This variant has been reported in an individual affected with Charcot Marie Tooth disease type 1 (PMID: 23838279). Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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
0.18
BayesDel_addAF
Uncertain
0.16
D
BayesDel_noAF
Uncertain
-0.010
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Benign
0.25
T;T;T;T;T
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Uncertain
0.92
.;.;.;.;D
M_CAP
Pathogenic
0.95
D
MetaRNN
Benign
0.22
T;T;T;T;T
MetaSVM
Uncertain
0.58
D
MutationAssessor
Benign
0.69
N;N;N;N;N
PhyloP100
1.1
PrimateAI
Uncertain
0.62
T
PROVEAN
Benign
-0.060
N;.;N;.;N
REVEL
Uncertain
0.47
Sift
Uncertain
0.028
D;.;D;.;D
Sift4G
Uncertain
0.021
D;.;D;.;D
Polyphen
0.99
D;D;D;D;D
Vest4
0.72
MVP
0.77
MPC
1.5
ClinPred
0.24
T
GERP RS
4.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.14
gMVP
0.88
Mutation Taster
=3/97
disease causing

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

Other links and lift over

dbSNP: rs200774406; hg19: chrX-70444269; COSMIC: COSV62139827; COSMIC: COSV62139827; API