rs1229066957

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000083.3(CLCN1):​c.908G>A​(p.Trp303*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,614,058 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 (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 stop_gained

Scores

5
1
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 9.99

Publications

3 publications found
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 Gene-Disease associations (from GenCC):
  • myotonia congenita, autosomal dominant
    Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
  • myotonia congenita, autosomal recessive
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • Thomsen and Becker disease
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 7-143330826-G-A is Pathogenic according to our data. Variant chr7-143330826-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 447075.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLCN1NM_000083.3 linkc.908G>A p.Trp303* stop_gained Exon 8 of 23 ENST00000343257.7 NP_000074.3 P35523
CLCN1NR_046453.2 linkn.1013G>A non_coding_transcript_exon_variant Exon 8 of 22

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkc.908G>A p.Trp303* stop_gained Exon 8 of 23 1 NM_000083.3 ENSP00000339867.2 P35523

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152174
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1461884
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
727240
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000135
AC:
15
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152174
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74332
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Apr 04, 2024
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PM2_moderate, PM3_supporting, PVS1 -

Jun 02, 2020
Athena Diagnostics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant creates a premature nonsense codon, and is therefore predicted to result in the loss of a functional protein. Found in at least one patient with expected phenotype for this gene, and not found in general population data. -

Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Pathogenic:1
Jan 23, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Trp303*) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with autosomal recessive Becker disease (PMID: 22197187, 24349310). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 447075). For these reasons, this variant has been classified as Pathogenic. -

Congenital myotonia, autosomal recessive form Pathogenic:1
Jun 18, 2024
Institute of Human Genetics, University of Leipzig Medical Center
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Criteria applied: PVS1,PM3,PM2_SUP -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.65
CADD
Pathogenic
44
DANN
Uncertain
1.0
Eigen
Pathogenic
0.90
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Pathogenic
0.99
D
PhyloP100
10
Vest4
0.74
GERP RS
4.6
Mutation Taster
=0/200
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1229066957; hg19: chr7-143027919; COSMIC: COSV58367701; API