NM_000083.3:c.762C>G

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PP2PP3PP5_Very_Strong

The NM_000083.3(CLCN1):​c.762C>G​(p.Cys254Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,612,064 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. C254C) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

9
9

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: -0.0320

Publications

4 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 12 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000083.3
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
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 7-143323374-C-G is Pathogenic according to our data. Variant chr7-143323374-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 664036.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000083.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CLCN1
NM_000083.3
MANE Select
c.762C>Gp.Cys254Trp
missense
Exon 6 of 23NP_000074.3P35523
CLCN1
NR_046453.2
n.864C>G
non_coding_transcript_exon
Exon 6 of 22

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CLCN1
ENST00000343257.7
TSL:1 MANE Select
c.762C>Gp.Cys254Trp
missense
Exon 6 of 23ENSP00000339867.2P35523
CLCN1
ENST00000455478.6
TSL:1
n.216C>G
non_coding_transcript_exon
Exon 3 of 7ENSP00000400027.2H7C1F4
CLCN1
ENST00000432192.6
TSL:1
n.463-199C>G
intron
N/AENSP00000395949.2H7C0N6

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152088
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:
0.000193
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
GnomAD2 exomes
AF:
0.0000278
AC:
7
AN:
251436
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000381
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000753
AC:
11
AN:
1459976
Hom.:
0
Cov.:
30
AF XY:
0.00000551
AC XY:
4
AN XY:
726404
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33430
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.000252
AC:
10
AN:
39690
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86222
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
9.01e-7
AC:
1
AN:
1110306
Other (OTH)
AF:
0.00
AC:
0
AN:
60312
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.484
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

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:
0.00000658
AC:
1
AN:
152088
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74290
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41400
American (AMR)
AF:
0.00
AC:
0
AN:
15268
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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:
0.00
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.0000330
AC:
4

ClinVar

ClinVar submissions
Significance:Pathogenic/Likely pathogenic
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
2
-
-
Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form (2)
1
-
-
Batten-Turner congenital myopathy (1)
1
-
-
Congenital myotonia, autosomal recessive form (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.22
BayesDel_addAF
Benign
-0.093
T
BayesDel_noAF
Uncertain
-0.040
CADD
Benign
20
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.57
D
Eigen
Benign
-0.34
Eigen_PC
Benign
-0.41
FATHMM_MKL
Uncertain
0.79
D
LIST_S2
Benign
0.86
D
M_CAP
Uncertain
0.25
D
MetaRNN
Benign
0.31
T
MetaSVM
Uncertain
0.16
D
MutationAssessor
Benign
0.20
N
PhyloP100
-0.032
PrimateAI
Benign
0.46
T
PROVEAN
Benign
-2.3
N
REVEL
Uncertain
0.56
Sift
Uncertain
0.020
D
Sift4G
Uncertain
0.026
D
Polyphen
0.99
D
Vest4
0.72
MutPred
0.40
Loss of stability (P = 0.1278)
MVP
0.89
MPC
0.84
ClinPred
0.38
T
GERP RS
0.067
Varity_R
0.50
gMVP
0.69
Mutation Taster
=34/66
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.57
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.57
Position offset: 12

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs772027125; hg19: chr7-143020467; COSMIC: COSV105915224; API