chr7-143346581-C-A

Variant summary

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

The NM_000083.3(CLCN1):​c.2287C>A​(p.Gln763Lys) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000049 in 1,612,984 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000052 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense, splice_region

Scores

19

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.619

Publications

2 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=0.096753985).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLCN1NM_000083.3 linkc.2287C>A p.Gln763Lys missense_variant, splice_region_variant Exon 19 of 23 ENST00000343257.7 NP_000074.3 P35523
CLCN1NR_046453.2 linkn.2242C>A splice_region_variant, non_coding_transcript_exon_variant Exon 18 of 22

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkc.2287C>A p.Gln763Lys missense_variant, splice_region_variant Exon 19 of 23 1 NM_000083.3 ENSP00000339867.2 P35523
CLCN1ENST00000432192.6 linkn.*1572C>A splice_region_variant, non_coding_transcript_exon_variant Exon 19 of 23 1 ENSP00000395949.2 H7C0N6
CLCN1ENST00000432192.6 linkn.*1572C>A 3_prime_UTR_variant Exon 19 of 23 1 ENSP00000395949.2 H7C0N6
CLCN1ENST00000650516.2 linkc.2287C>A p.Gln763Lys missense_variant, splice_region_variant Exon 19 of 23 ENSP00000498052.2 A0A3B3IU72

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152158
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000480
AC:
12
AN:
249774
AF XY:
0.0000666
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000107
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000520
AC:
76
AN:
1460826
Hom.:
0
Cov.:
32
AF XY:
0.0000578
AC XY:
42
AN XY:
726808
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33462
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86178
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53186
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000657
AC:
73
AN:
1111322
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60362
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.451
Heterozygous variant carriers
0
4
9
13
18
22
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:
0.0000197
AC:
3
AN:
152158
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74334
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41420
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.608
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:
0.0000567
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000576
AC:
7
EpiCase
AF:
0.00
EpiControl
AF:
0.000178

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1
Nov 26, 2019
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
Sep 16, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamine, which is neutral and polar, with lysine, which is basic and polar, at codon 763 of the CLCN1 protein (p.Gln763Lys). This variant is present in population databases (rs754581538, gnomAD 0.01%). This missense change has been observed in individual(s) with autosomal dominant myotonia congenita and/or myotonia congenita (PMID: 23739125, 36212636). ClinVar contains an entry for this variant (Variation ID: 462838). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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
0.068
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.37
CADD
Benign
15
DANN
Benign
0.57
DEOGEN2
Benign
0.11
T
Eigen
Benign
-0.84
Eigen_PC
Benign
-0.73
FATHMM_MKL
Benign
0.080
N
LIST_S2
Benign
0.49
T
M_CAP
Benign
0.021
T
MetaRNN
Benign
0.097
T
MetaSVM
Benign
-0.73
T
MutationAssessor
Benign
1.1
L
PhyloP100
0.62
PrimateAI
Benign
0.32
T
PROVEAN
Benign
-0.51
N
REVEL
Benign
0.25
Sift
Benign
0.85
T
Sift4G
Benign
0.88
T
Polyphen
0.0070
B
Vest4
0.26
MutPred
0.45
Gain of solvent accessibility (P = 9e-04);
MVP
0.81
MPC
0.24
ClinPred
0.025
T
GERP RS
2.5
Varity_R
0.057
gMVP
0.32
Mutation Taster
=90/10
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
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: rs754581538; hg19: chr7-143043674; API