rs80356686

Positions:

chr7-143321729-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PP3_StrongPP5

The NM_000083.3(CLCN1):c.577G>A(p.Glu193Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,614,096 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:1

Conservation

PhyloP100: 10.0

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]

CLCN1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM1

In a helix (size 7) 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, 0.988

PP5

Variant 7-143321729-G-A is Pathogenic according to our data. Variant chr7-143321729-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 21045.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1}. Variant chr7-143321729-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CLCN1	NM_000083.3 linkuse as main transcript	c.577G>A	p.Glu193Lys	missense_variant	5/23	ENST00000343257.7	NP_000074.3
CLCN1	NR_046453.2 linkuse as main transcript	n.679G>A		non_coding_transcript_exon_variant	5/22

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CLCN1	ENST00000343257.7 linkuse as main transcript	c.577G>A	p.Glu193Lys	missense_variant	5/23	1	NM_000083.3	ENSP00000339867	P4

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152210

Hom.:

Cov.:

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:

0.0000278

AC:

AN:

251482

Hom.:

AF XY:

0.0000294

AC XY:

AN XY:

135920

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:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000527

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000150

AC:

AN:

1461886

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

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:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74368

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:

0.00000756

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Congenital myotonia, autosomal recessive form

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 01, 2024	Variant summary: CLCN1 c.577G>A (p.Glu193Lys) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 251482 control chromosomes. c.577G>A has been reported in the literature in three individuals in one family affected with Myotonia congenita (Colding-Jorgensen_2003, Grunnet_2003). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. This study shows that this variant results in with a rightward shift in the currentvoltage (I/V) relationship, a typical effect of dominant CLCN1 mutants on the channel protein (Grunnet_2003). The following publications have been ascertained in the context of this evaluation (PMID: 12661046, 14639587). ClinVar contains an entry for this variant (Variation ID: 21045). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India	-	In-silico analysis tools (REVEL, CADD_phred, GERP, MutationTaster) are consistent in predicting the variant to impair CLCN1 protein function. The variant c.577G>A has been reported as likely pathogenic/uncertain significance by two submitters to the ClinVar database. This missense has been observed in individuals with myotonic congenita (ClinVar: 21045; Colding-Jørgensen et al., 2003; Grunnet M et al., 2003). The clinical features observed in the proband are in concordance with Myotonia congenita. -

Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 17, 2023

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 193 of the CLCN1 protein (p.Glu193Lys). This variant is present in population databases (rs80356686, gnomAD 0.004%). This missense change has been observed in individual(s) with autosomal dominant and autosomal recessive myotonia congenita (PMID: 12661046; Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 21045). 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: 14639587). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Dec 09, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.52

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.95

.;D

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.92

FATHMM_MKL

Uncertain

0.94

LIST_S2

Pathogenic

1.0

D;D

M_CAP

Pathogenic

0.53

MetaRNN

Pathogenic

0.99

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.0

.;H

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.79

PROVEAN

Uncertain

-3.8

.;D

REVEL

Pathogenic

0.95

Sift

Uncertain

0.0010

.;D

Sift4G

Uncertain

0.0020

.;D

Polyphen

1.0

.;D

Vest4

0.99

MutPred

0.93

Gain of MoRF binding (P = 0.0384);Gain of MoRF binding (P = 0.0384);

MVP

0.98

MPC

0.79

ClinPred

1.0

GERP RS

5.0

Varity_R

0.96

gMVP

0.96

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