rs749205522

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PP3_ModeratePP5_Very_Strong

The NM_000083.3(CLCN1):​c.2551G>A​(p.Val851Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000217 in 1,614,008 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

10
8
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 5.36
Variant links:
Genes affected
CLCN1 (HGNC:2019): (chloride voltage-gated channel 1) The CLCN family of voltage-dependent chloride channel genes comprises nine members (CLCN1-7, Ka and Kb) which demonstrate quite diverse functional characteristics while sharing significant sequence homology. The protein encoded by this gene regulates the electric excitability of the skeletal muscle membrane. Mutations in this gene cause two forms of inherited human muscle disorders: recessive generalized myotonia congenita (Becker) and dominant myotonia (Thomsen). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2012]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.906
PP5
Variant 7-143350610-G-A is Pathogenic according to our data. Variant chr7-143350610-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 582345.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
CLCN1NM_000083.3 linkuse as main transcriptc.2551G>A p.Val851Met missense_variant 22/23 ENST00000343257.7 NP_000074.3
CLCN1NR_046453.2 linkuse as main transcriptn.2506G>A non_coding_transcript_exon_variant 21/22

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkuse as main transcriptc.2551G>A p.Val851Met missense_variant 22/231 NM_000083.3 ENSP00000339867 P4
CLCN1ENST00000432192.6 linkuse as main transcriptc.*1836G>A 3_prime_UTR_variant, NMD_transcript_variant 22/231 ENSP00000395949
CLCN1ENST00000650516.2 linkuse as main transcriptc.2551G>A p.Val851Met missense_variant 22/23 ENSP00000498052 A2

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152130
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
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:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000239
AC:
6
AN:
251482
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135916
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000289
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:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000198
AC:
29
AN:
1461878
Hom.:
0
Cov.:
32
AF XY:
0.0000151
AC XY:
11
AN XY:
727240
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000216
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152130
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74314
show subpopulations
Gnomad4 AFR
AF:
0.0000724
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000441
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000302
ExAC
AF:
0.0000330
AC:
4
Asia WGS
AF:
0.000577
AC:
2
AN:
3478
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingAthena DiagnosticsSep 27, 2019The frequency of this variant in the general population is consistent with pathogenicity. Found in at least one patient with expected phenotype for this gene. Predicted to have a damaging effect on the protein. Assessment of experimental evidence suggests this variant results in abnormal protein function. -
Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 05, 2024This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 851 of the CLCN1 protein (p.Val851Met). This variant is present in population databases (rs749205522, gnomAD 0.01%). This missense change has been observed in individual(s) with autosomal recessive myotonia congenita (PMID: 22094069, 23739125, 29935101, 32117024). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant has been reported in individual(s) with autosomal dominant myotonia congenita (PMID: 29935101, 32117024); however, the role of the variant in this condition is currently unclear. ClinVar contains an entry for this variant (Variation ID: 582345). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CLCN1 protein function. Experimental studies have shown that this missense change affects CLCN1 function (PMID: 29935101). For these reasons, this variant has been classified as Pathogenic. -
Congenital myotonia, autosomal dominant form Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingDASAFeb 05, 2022The c.2551G>A;p.(Val851Met) missense variant has been observed in affected individual(s) and ClinVar contains an entry for this variant (ClinVar ID: 582345; PMID: 32117024; 29935101; 22094069; 23739125; 29935101) - PS4. The variant is present at low allele frequencies population databases (rs749205522 – gnomAD 0.0003944%; ABraOM no frequency - http://abraom.ib.usp.br/) - PM2_supporting. The variant co-segregated with disease in multiple affected family members (PMID: 32117024) - PP1. Multiple lines of computational evidence support a deleterious effect on the gene or gene product - PP3. The variant was observed in trans with a pathogenic variant for a fully penetrant dominant gene/disorder or observed in cis with a pathogenic variant in any inheritance pattern (PMID: 32117024) BP2. In summary, the currently available evidence indicates that the variant is likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.38
D
BayesDel_noAF
Pathogenic
0.49
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.79
D
Eigen
Pathogenic
0.78
Eigen_PC
Uncertain
0.66
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Uncertain
0.97
D
M_CAP
Uncertain
0.23
D
MetaRNN
Pathogenic
0.91
D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.5
M
MutationTaster
Benign
1.0
D
PrimateAI
Pathogenic
0.85
D
PROVEAN
Uncertain
-2.8
D
REVEL
Pathogenic
0.81
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0010
D
Polyphen
1.0
D
Vest4
0.91
MutPred
0.73
Loss of sheet (P = 0.1398);
MVP
0.97
MPC
0.56
ClinPred
0.84
D
GERP RS
4.2
Varity_R
0.48
gMVP
0.82

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.

Other links and lift over

dbSNP: rs749205522; hg19: chr7-143047703; COSMIC: COSV104660662; COSMIC: COSV104660662; API