7-143345637-G-C

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_000083.3(CLCN1):​c.2047G>C​(p.Glu683Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000121 in 1,564,124 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict 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. E683A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

1
6
12

Clinical Significance

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

Conservation

PhyloP100: 4.61

Publications

0 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: Likely_benign. The variant received -1 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.
BP4
Computational evidence support a benign effect (MetaRNN=0.23301321).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLCN1NM_000083.3 linkc.2047G>C p.Glu683Gln missense_variant Exon 17 of 23 ENST00000343257.7 NP_000074.3 P35523
CLCN1NR_046453.2 linkn.2002G>C non_coding_transcript_exon_variant Exon 16 of 22

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkc.2047G>C p.Glu683Gln missense_variant Exon 17 of 23 1 NM_000083.3 ENSP00000339867.2 P35523
CLCN1ENST00000432192.6 linkn.*1332G>C non_coding_transcript_exon_variant Exon 17 of 23 1 ENSP00000395949.2 H7C0N6
CLCN1ENST00000432192.6 linkn.*1332G>C 3_prime_UTR_variant Exon 17 of 23 1 ENSP00000395949.2 H7C0N6
CLCN1ENST00000650516.2 linkc.2047G>C p.Glu683Gln missense_variant Exon 17 of 23 ENSP00000498052.2 A0A3B3IU72

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152202
Hom.:
0
Cov.:
31
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000116
AC:
2
AN:
171786
AF XY:
0.0000218
show subpopulations
Gnomad AFR exome
AF:
0.000104
Gnomad AMR exome
AF:
0.0000380
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.0000113
AC:
16
AN:
1411922
Hom.:
0
Cov.:
33
AF XY:
0.0000100
AC XY:
7
AN XY:
697844
show subpopulations
African (AFR)
AF:
0.0000310
AC:
1
AN:
32296
American (AMR)
AF:
0.0000269
AC:
1
AN:
37242
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25264
East Asian (EAS)
AF:
0.00
AC:
0
AN:
36756
South Asian (SAS)
AF:
0.00
AC:
0
AN:
80246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49378
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5286
European-Non Finnish (NFE)
AF:
0.0000129
AC:
14
AN:
1086988
Other (OTH)
AF:
0.00
AC:
0
AN:
58466
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.441
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.0000197
AC:
3
AN:
152202
Hom.:
0
Cov.:
31
AF XY:
0.0000134
AC XY:
1
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
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:
0.0000282
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000341
AC:
4

ClinVar

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

Submissions by phenotype

not provided Uncertain:2
Feb 05, 2023
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 does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Jan 19, 2021
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 18, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with glutamine, which is neutral and polar, at codon 683 of the CLCN1 protein (p.Glu683Gln). This variant is present in population databases (rs760351874, gnomAD 0.006%). 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: 462836). 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CLCN1 protein function. 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
Benign
0.13
BayesDel_addAF
Benign
-0.15
T
BayesDel_noAF
Benign
-0.24
CADD
Benign
22
DANN
Uncertain
0.99
DEOGEN2
Benign
0.18
T
Eigen
Benign
0.17
Eigen_PC
Uncertain
0.24
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.87
D
M_CAP
Benign
0.030
D
MetaRNN
Benign
0.23
T
MetaSVM
Uncertain
-0.23
T
MutationAssessor
Uncertain
2.4
M
PhyloP100
4.6
PrimateAI
Uncertain
0.77
T
PROVEAN
Benign
-1.0
N
REVEL
Benign
0.21
Sift
Benign
0.18
T
Sift4G
Benign
0.13
T
Polyphen
0.73
P
Vest4
0.27
MutPred
0.26
Loss of ubiquitination at K680 (P = 0.0247);
MVP
0.90
MPC
0.21
ClinPred
0.41
T
GERP RS
4.4
Varity_R
0.20
gMVP
0.41
Mutation Taster
=82/18
polymorphism

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: rs760351874; hg19: chr7-143042730; API