7-143321787-T-C

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PP2PP3_Strong

The NM_000083.3(CLCN1):​c.635T>C​(p.Phe212Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000489 in 1,614,130 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging 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. F212C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

15
3
1

Clinical Significance

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

Conservation

PhyloP100: 8.02

Publications

1 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: Uncertain_significance. The variant received 5 ACMG points.

PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 106 curated pathogenic missense variants (we use a threshold of 10). The gene has 18 curated benign missense variants. Gene score misZ: 0.21191 (below the threshold of 3.09). Trascript score misZ: 0.95247 (below the threshold of 3.09). GenCC associations: The gene is linked to myotonia congenita, autosomal dominant, myotonia congenita, autosomal recessive, Thomsen and Becker disease.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.971

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLCN1NM_000083.3 linkc.635T>C p.Phe212Ser missense_variant Exon 5 of 23 ENST00000343257.7 NP_000074.3 P35523
CLCN1NR_046453.2 linkn.737T>C non_coding_transcript_exon_variant Exon 5 of 22

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkc.635T>C p.Phe212Ser missense_variant Exon 5 of 23 1 NM_000083.3 ENSP00000339867.2 P35523

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152238
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
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
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251458
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000513
AC:
75
AN:
1461892
Hom.:
0
Cov.:
33
AF XY:
0.0000550
AC XY:
40
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000656
AC:
73
AN:
1112010
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
4
8
13
17
21
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000263
AC:
4
AN:
152238
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74376
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68050
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.00
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Sep 26, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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; Has not been previously published as pathogenic or benign to our knowledge -

Aug 04, 2022
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Uncertain:1
Jan 15, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 212 of the CLCN1 protein (p.Phe212Ser). This variant is present in population databases (rs201113768, gnomAD 0.008%). This missense change has been observed in individual(s) with clinical features of CLCN1-related conditions (internal data). ClinVar contains an entry for this variant (Variation ID: 531750). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt CLCN1 protein function with a positive predictive value of 95%. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.93
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.44
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.80
.;D
Eigen
Pathogenic
0.78
Eigen_PC
Pathogenic
0.71
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.67
D
MetaRNN
Pathogenic
0.97
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.2
.;M
PhyloP100
8.0
PrimateAI
Pathogenic
0.80
T
PROVEAN
Pathogenic
-5.7
.;D
REVEL
Pathogenic
0.97
Sift
Uncertain
0.0020
.;D
Sift4G
Uncertain
0.0040
.;D
Polyphen
1.0
.;D
Vest4
0.91
MutPred
0.83
Loss of stability (P = 0.019);Loss of stability (P = 0.019);
MVP
0.99
MPC
1.0
ClinPred
0.99
D
GERP RS
5.0
Varity_R
0.96
gMVP
0.88
Mutation Taster
=17/83
disease causing

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: rs201113768; hg19: chr7-143018880; API