rs121912805

Variant summary

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

The NM_000083.3(CLCN1):​c.871G>A​(p.Glu291Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,992 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

17
1
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM1
In a helix (size 9) in uniprot entity CLCN1_HUMAN there are 10 pathogenic changes around while only 0 benign (100%) in NM_000083.3
PP3
MetaRNN computational evidence supports a deleterious effect, 0.989
PP5
Variant 7-143330789-G-A is Pathogenic according to our data. Variant chr7-143330789-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 17541.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-143330789-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.871G>A p.Glu291Lys missense_variant 8/23 ENST00000343257.7 NP_000074.3
CLCN1NR_046453.2 linkuse as main transcriptn.976G>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.871G>A p.Glu291Lys missense_variant 8/231 NM_000083.3 ENSP00000339867 P4

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152126
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:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251366
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135860
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:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000410
AC:
6
AN:
1461866
Hom.:
0
Cov.:
32
AF XY:
0.00000550
AC XY:
4
AN XY:
727236
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:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000450
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152126
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74318
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:
0.000207
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Likely pathogenic, criteria provided, single submitterclinical testingRevvity Omics, RevvityOct 12, 2021- -
Pathogenic, criteria provided, single submitterclinical testingGeneDxApr 08, 2022Published functional studies demonstrate the variant results in loss of channel activity in a recessive manner (Pusch et al., 1995); Not observed at significant frequency in large population cohorts (gnomAD); 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: 11933197, 24349310, 34790634, 10508236, 34142127, 11137655, 19185184, 9736777, 8845168, 8533761, 23739125, 35170402, 27415035, 28662944, 32660787) -
Congenital myotonia, autosomal dominant form Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingInstitute of Human Genetics Munich, Klinikum Rechts Der Isar, TU MünchenNov 09, 2020- -
Pathogenic, criteria provided, single submitterclinical testingCenter for Genomic Medicine, King Faisal Specialist Hospital and Research CenterApr 04, 2024- -
Congenital myotonia, autosomal recessive form Pathogenic:2
Pathogenic, no assertion criteria providedliterature onlyOMIMJun 21, 2019- -
Likely pathogenic, criteria provided, single submitterclinical testingMGZ Medical Genetics CenterJul 12, 2022- -
Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 30, 2023This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 291 of the CLCN1 protein (p.Glu291Lys). This variant is present in population databases (rs121912805, gnomAD 0.0009%). This missense change has been observed in individual(s) with autosomal recessive myotonia congenita (PMID: 8845168, 23739125, 27415035). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 17541). 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: 8845168). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
1.0
BayesDel_addAF
Pathogenic
0.56
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
34
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.96
.;D
Eigen
Pathogenic
0.98
Eigen_PC
Pathogenic
0.86
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
1.0
D;D
M_CAP
Pathogenic
0.83
D
MetaRNN
Pathogenic
0.99
D;D
MetaSVM
Pathogenic
0.99
D
MutationAssessor
Pathogenic
4.5
.;H
MutationTaster
Benign
1.0
A
PrimateAI
Pathogenic
0.94
D
PROVEAN
Uncertain
-3.7
.;D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
.;D
Sift4G
Pathogenic
0.0
.;D
Polyphen
1.0
.;D
Vest4
0.99
MutPred
0.96
Gain of MoRF binding (P = 0.0184);Gain of MoRF binding (P = 0.0184);
MVP
0.99
MPC
0.79
ClinPred
1.0
D
GERP RS
4.6
Varity_R
0.98
gMVP
0.99

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs121912805; hg19: chr7-143027882; COSMIC: COSV58367720; API