rs146469288

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP4

The NM_000083.3(CLCN1):c.1831C>T(p.Arg611Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,613,986 control chromosomes in the GnomAD database, including 1 homozygotes. 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. R611H) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000011 ( 1 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 1.75

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_benign. Variant got -1 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.3700488).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLCN1	NM_000083.3 linkuse as main transcript	c.1831C>T	p.Arg611Cys	missense_variant	16/23	ENST00000343257.7
CLCN1	NR_046453.2 linkuse as main transcript	n.1786C>T		non_coding_transcript_exon_variant	15/22

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
CLCN1	ENST00000343257.7 linkuse as main transcript	c.1831C>T	p.Arg611Cys	missense_variant	16/23	1	NM_000083.3	P4
CLCN1	ENST00000432192.6 linkuse as main transcript	c.*1116C>T		3_prime_UTR_variant, NMD_transcript_variant	16/23	1
CLCN1	ENST00000650516.2 linkuse as main transcript	c.1831C>T	p.Arg611Cys	missense_variant	16/23			A2

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152122

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000795

AC:

AN:

251460

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135916

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000109

AC:

AN:

1461864

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727234

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000809

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152122

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74330

show subpopulations

Gnomad4 AFR

AF:

0.000121

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000604

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Aug 02, 2018

- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 03, 2022

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 611 of the CLCN1 protein (p.Arg611Cys). This variant is present in population databases (rs146469288, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with CLCN1-related conditions. ClinVar contains an entry for this variant (Variation ID: 585685). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15"). 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. -

Congenital myotonia, autosomal recessive form

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Neuberg Centre For Genomic Medicine, NCGM

The missense variant c.1831C>T (p.Arg611Cys) has been submitted to ClinVar as a Variant of Uncertain Significance, but no details are available for independent assessment. It has not been reported in affected individuals. The p.Arg611Cys variant is reported with the allele frequency (0.001%) in the gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. The amino acid Arg at position 611 is changed to a Cys changing protein sequence and it might alter its composition and physico-chemical properties. The variant is predicted to be damaging by SIFT and the residue is conserved across species. The amino acid change p.Arg611Cys in CLCN1 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Variant of Uncertain Significance (VUS). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

0.0038

BayesDel_noAF

Uncertain

-0.060

Cadd

Uncertain

Dann

Uncertain

1.0

DEOGEN2

Uncertain

0.61

Eigen

Uncertain

0.42

Eigen_PC

Uncertain

0.47

FATHMM_MKL

Uncertain

0.90

LIST_S2

Pathogenic

0.98

M_CAP

Benign

0.057

MetaRNN

Benign

0.37

MetaSVM

Uncertain

-0.012

MutationAssessor

Benign

1.7

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.61

PROVEAN

Pathogenic

-6.5

REVEL

Uncertain

0.51

Sift

Uncertain

0.026

Sift4G

Uncertain

0.044

Polyphen

0.63

Vest4

0.30

MVP

0.91

MPC

0.31

ClinPred

0.97

GERP RS

4.9

Varity_R

0.24

gMVP

0.64

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.18

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