rs201714423

Positions:

chr7-143331615-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000083.3(CLCN1):c.1129C>T(p.Arg377Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000136 in 1,614,040 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R377R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

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

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 4.76

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 Pathogenic. Variant got 16 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PP5

Variant 7-143331615-C-T is Pathogenic according to our data. Variant chr7-143331615-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 447045.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-143331615-C-T is described in Lovd as [Pathogenic]. Variant chr7-143331615-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLCN1	NM_000083.3 linkuse as main transcript	c.1129C>T	p.Arg377Ter	stop_gained	10/23	ENST00000343257.7
CLCN1	NR_046453.2 linkuse as main transcript	n.1234C>T		non_coding_transcript_exon_variant	10/22

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
CLCN1	ENST00000343257.7 linkuse as main transcript	c.1129C>T	p.Arg377Ter	stop_gained	10/23	1	NM_000083.3	P4
CLCN1	ENST00000432192.6 linkuse as main transcript	c.*414C>T		3_prime_UTR_variant, NMD_transcript_variant	10/23	1
CLCN1	ENST00000650516.2 linkuse as main transcript	c.1129C>T	p.Arg377Ter	stop_gained	10/23			A2

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152154

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:

0.0000943

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251462

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135902

show subpopulations

Gnomad AFR exome

AF:

0.000185

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000130

AC:

AN:

1461768

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

727190

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000894

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:

0.00000899

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152272

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74456

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:

0.0000943

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000473

Bravo

AF:

0.0000113

ExAC

AF:

0.0000165

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Nov 10, 2023	Reported in association with autosomal recessive myotonia congenita in the published literature (PMID: 28325641, 17932099); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 31589614, 34938096, 32721234, 17932099, 23893571, 25525159, 31069529, 34529042, 28325641) -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	Oct 31, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Aug 02, 2019	- -

CLCN1-related disorder

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Nov 16, 2023

The CLCN1 c.1129C>T variant is predicted to result in premature protein termination (p.Arg377*). This variant has been reported in the homozygous or compound heterozygous states in three patients with myotonia congenita (Fialho et al 2007. PubMed ID: 17932099; Modoni et al 2011. PubMed ID: 21221019), and in one patient with myotonia congenita in which a second potentially pathogenic variant was not identified (Sun et al 2020. PubMed ID: 31567646). This variant is reported in 0.012% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/7-143028708-C-T). Nonsense variants in CLCN1 are expected to be pathogenic. This variant is interpreted as pathogenic. -

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

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 24, 2023

This sequence change creates a premature translational stop signal (p.Arg377*) in the CLCN1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CLCN1 are known to be pathogenic (PMID: 17932099, 22094069, 23739125). This variant is present in population databases (rs201714423, gnomAD 0.004%). This premature translational stop signal has been observed in individual(s) with autosomal recessive myotonia congenita (PMID: 21221019). ClinVar contains an entry for this variant (Variation ID: 447045). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.53

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.85

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Uncertain

0.85

MutationTaster

Benign

1.0

Vest4

0.95

GERP RS

5.1

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.22

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.22

Position offset: 37

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