rs1212604561

Variant summary

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

The NM_000083.3(CLCN1):​c.1988G>A​(p.Arg663His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000573 in 1,395,666 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 0.0000057 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.00

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: 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=0.1728467).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLCN1NM_000083.3 linkc.1988G>A p.Arg663His missense_variant Exon 17 of 23 ENST00000343257.7 NP_000074.3 P35523
CLCN1NR_046453.2 linkn.1943G>A 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.1988G>A p.Arg663His missense_variant Exon 17 of 23 1 NM_000083.3 ENSP00000339867.2 P35523
CLCN1ENST00000432192.6 linkn.*1273G>A non_coding_transcript_exon_variant Exon 17 of 23 1 ENSP00000395949.2 H7C0N6
CLCN1ENST00000432192.6 linkn.*1273G>A 3_prime_UTR_variant Exon 17 of 23 1 ENSP00000395949.2 H7C0N6
CLCN1ENST00000650516.2 linkc.1988G>A p.Arg663His missense_variant Exon 17 of 23 ENSP00000498052.2 A0A3B3IU72

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD2 exomes
AF:
0.0000129
AC:
2
AN:
155580
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000176
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000573
AC:
8
AN:
1395666
Hom.:
0
Cov.:
33
AF XY:
0.00000291
AC XY:
2
AN XY:
687682
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31542
American (AMR)
AF:
0.00
AC:
0
AN:
35636
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25160
East Asian (EAS)
AF:
0.000224
AC:
8
AN:
35676
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79154
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48864
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4996
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1076896
Other (OTH)
AF:
0.00
AC:
0
AN:
57742
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
2
3
4
5
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
Cov.:
31
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Uncertain:1
Jun 12, 2019
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine with histidine at codon 663 of the CLCN1 protein (p.Arg663His). The arginine residue is moderately conserved and there is a small physicochemical difference between arginine and histidine. The frequency data for this variant in the population databases is unreliable, as metrics indicate poor quality at this position in the ExAC database. This variant has not been reported in the literature in individuals with a CLCN1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The histidine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies. In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.070
BayesDel_addAF
Benign
-0.082
T
BayesDel_noAF
Benign
-0.36
CADD
Benign
22
DANN
Uncertain
1.0
DEOGEN2
Benign
0.26
T
Eigen
Benign
-0.19
Eigen_PC
Benign
-0.099
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.33
T
M_CAP
Benign
0.025
T
MetaRNN
Benign
0.17
T
MetaSVM
Benign
-0.57
T
MutationAssessor
Uncertain
2.6
M
PhyloP100
2.0
PrimateAI
Benign
0.47
T
PROVEAN
Benign
-2.2
N
REVEL
Benign
0.24
Sift
Benign
0.067
T
Sift4G
Benign
0.097
T
Polyphen
0.0060
B
Vest4
0.094
MutPred
0.49
Loss of MoRF binding (P = 0.0156);
MVP
0.82
MPC
0.23
ClinPred
0.34
T
GERP RS
1.4
Varity_R
0.098
gMVP
0.42
Mutation Taster
=61/39
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.14
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: rs1212604561; hg19: chr7-143042671; COSMIC: COSV58369738; API