rs80356692

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PP3_StrongPP5_Very_Strong

The NM_000083.3(CLCN1):​c.937G>A​(p.Ala313Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000805 in 1,614,070 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 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

16
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11

Conservation

PhyloP100: 9.99
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM1
In a transmembrane_region Helical (size 19) in uniprot entity CLCN1_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_000083.3
PP3
MetaRNN computational evidence supports a deleterious effect, 0.973
PP5
Variant 7-143330855-G-A is Pathogenic according to our data. Variant chr7-143330855-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 21052.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-143330855-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
CLCN1NM_000083.3 linkuse as main transcriptc.937G>A p.Ala313Thr missense_variant 8/23 ENST00000343257.7 NP_000074.3
CLCN1NR_046453.2 linkuse as main transcriptn.1042G>A non_coding_transcript_exon_variant 8/22

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkuse as main transcriptc.937G>A p.Ala313Thr missense_variant 8/231 NM_000083.3 ENSP00000339867 P4

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152180
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251428
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135878
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000752
AC:
11
AN:
1461890
Hom.:
0
Cov.:
32
AF XY:
0.0000110
AC XY:
8
AN XY:
727248
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:
0.00000989
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152180
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74336
show subpopulations
Gnomad4 AFR
AF:
0.0000241
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:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:11
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:5
Pathogenic, criteria provided, single submitterclinical testingAthena DiagnosticsMay 05, 2023The frequency of this variant in the general population is consistent with pathogenicity (Genome Aggregation Database (gnomAD), Cambridge, MA (URL: http://gnomad.broadinstitute.org)). This variant is associated with autosomal dominant myotonia congenita in most families (PMID: 9566422, 17932099, 23893571, 24037712,31970219), however, it has been associated with autosomal recessive myotonia congenita in at least one family (PMID: 9566422, 23893571). At least one other missense variant at this codon is considered to be pathogenic or likely pathogenic, suggesting this variant may also cause disease. Assessment of experimental evidence suggests this variant results in abnormal protein function. This variant leads to decrease in current at physiologic voltages due to a positive shift in the voltage dependence of activation (PMID: 9736777, 17042925, 11408615). -
Pathogenic, criteria provided, single submitterclinical testingCenter for Pediatric Genomic Medicine, Children's Mercy Hospital and ClinicsMay 09, 2016- -
Pathogenic, criteria provided, single submitterclinical testingRevvity Omics, RevvityApr 23, 2019- -
Pathogenic, criteria provided, single submitterclinical testingGeneDxJul 13, 2021Published functional studies demonstrate a damaging effect resulting in a positive voltage shift that creates a dominant negative effect on wild type channels and decrease in maximal amplitude (Kubisch et al., 1998; Tan et al., 2014); Not observed at significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 9736777, 23893571, 31589614, 29896741, 27535533, 32670189, 28427807, 9566422, 23820649, 12163078, 24037712, 12566541, 15786415, 17042925, 16786525, 15389891, 10533075, 17654559, 24349310, 17932099, 23113340, 19697366, 11408615, 11933197, 23225051) -
Pathogenic, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenSep 01, 2020- -
Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsMay 08, 2022- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 20, 2023This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 313 of the CLCN1 protein (p.Ala313Thr). This variant is present in population databases (rs80356692, gnomAD 0.0009%). This missense change has been observed in individuals with autosomal dominant and autosomal recessive myotonia congenita (PMID: 17654559, 17932099, 23225051, 23893571). It has also been observed to segregate with disease in related individuals. This variant is also known as c.1024G>A. ClinVar contains an entry for this variant (Variation ID: 21052). 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) performed at Invitae indicates that this missense variant is expected to disrupt CLCN1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects CLCN1 function (PMID: 9736777). For these reasons, this variant has been classified as Pathogenic. -
Congenital myotonia, autosomal dominant form Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingLaboratory of Medical Genetics, National & Kapodistrian University of AthensFeb 20, 2024- -
Pathogenic, criteria provided, single submitterclinical testingInstitute of Immunology and Genetics KaiserslauternDec 06, 2022ACMG Criteria: PS3, PM1, PM2_P, PM5, PP3, PP5; Variant was found in heterozygous state. -
Congenital myotonia, autosomal recessive form Pathogenic:2
Likely pathogenic, criteria provided, single submitterclinical testingCentre for Mendelian Genomics, University Medical Centre LjubljanaJan 01, 2016This variant was classified as: Likely pathogenic. The following ACMG criteria were applied in classifying this variant: PS1,PP2,PP3. -
Pathogenic, criteria provided, single submitterclinical testingMGZ Medical Genetics CenterDec 22, 2021- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.80
BayesDel_addAF
Pathogenic
0.49
D
BayesDel_noAF
Pathogenic
0.46
CADD
Pathogenic
34
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.82
.;D
Eigen
Pathogenic
0.72
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.65
D
MetaRNN
Pathogenic
0.97
D;D
MetaSVM
Pathogenic
0.88
D
MutationAssessor
Uncertain
2.1
.;M
MutationTaster
Benign
1.0
A
PrimateAI
Pathogenic
0.82
D
PROVEAN
Uncertain
-3.7
.;D
REVEL
Pathogenic
0.86
Sift
Pathogenic
0.0
.;D
Sift4G
Pathogenic
0.0
.;D
Polyphen
1.0
.;D
Vest4
0.87
MutPred
0.88
Loss of stability (P = 0.091);Loss of stability (P = 0.091);
MVP
0.98
MPC
0.73
ClinPred
0.99
D
GERP RS
4.6
Varity_R
0.92
gMVP
0.83

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: rs80356692; hg19: chr7-143027948; API