rs118066140

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 4P and 9B. PM1PM5BP4_StrongBP6BS2

The ENST00000343257.7(CLCN1):​c.899G>A​(p.Arg300Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00708 in 1,614,162 control chromosomes in the GnomAD database, including 46 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R300W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0046 ( 1 hom., cov: 32)
Exomes 𝑓: 0.0073 ( 45 hom. )

Consequence

CLCN1
ENST00000343257.7 missense

Scores

9
6
4

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:11

Conservation

PhyloP100: 8.13
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

PM1
In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in ENST00000343257.7
PM5
Other missense variant is known to change same aminoacid residue: Variant chr7-143330816-C-T is described in Lovd as [Pathogenic].
BP4
Computational evidence support a benign effect (MetaRNN=0.016606092).
BP6
Variant 7-143330817-G-A is Benign according to our data. Variant chr7-143330817-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 252463.We mark this variant Likely_benign, oryginal submissions are: {Benign=6, Uncertain_significance=1, Likely_benign=3}. Variant chr7-143330817-G-A is described in Lovd as [Pathogenic]. Variant chr7-143330817-G-A is described in Lovd as [Benign].
BS2
High Homozygotes in GnomAdExome4 at 45 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
CLCN1NM_000083.3 linkuse as main transcriptc.899G>A p.Arg300Gln missense_variant 8/23 ENST00000343257.7 NP_000074.3
CLCN1NR_046453.2 linkuse as main transcriptn.1004G>A non_coding_transcript_exon_variant 8/22

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkuse as main transcriptc.899G>A p.Arg300Gln missense_variant 8/231 NM_000083.3 ENSP00000339867 P4

Frequencies

GnomAD3 genomes
AF:
0.00459
AC:
698
AN:
152168
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00167
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00288
Gnomad ASJ
AF:
0.000576
Gnomad EAS
AF:
0.000385
Gnomad SAS
AF:
0.00622
Gnomad FIN
AF:
0.00122
Gnomad MID
AF:
0.00316
Gnomad NFE
AF:
0.00783
Gnomad OTH
AF:
0.00192
GnomAD3 exomes
AF:
0.00475
AC:
1195
AN:
251402
Hom.:
5
AF XY:
0.00498
AC XY:
677
AN XY:
135866
show subpopulations
Gnomad AFR exome
AF:
0.000984
Gnomad AMR exome
AF:
0.00205
Gnomad ASJ exome
AF:
0.000794
Gnomad EAS exome
AF:
0.000381
Gnomad SAS exome
AF:
0.00480
Gnomad FIN exome
AF:
0.00115
Gnomad NFE exome
AF:
0.00785
Gnomad OTH exome
AF:
0.00456
GnomAD4 exome
AF:
0.00734
AC:
10728
AN:
1461876
Hom.:
45
Cov.:
32
AF XY:
0.00729
AC XY:
5303
AN XY:
727238
show subpopulations
Gnomad4 AFR exome
AF:
0.00105
Gnomad4 AMR exome
AF:
0.00235
Gnomad4 ASJ exome
AF:
0.000880
Gnomad4 EAS exome
AF:
0.000176
Gnomad4 SAS exome
AF:
0.00512
Gnomad4 FIN exome
AF:
0.00180
Gnomad4 NFE exome
AF:
0.00871
Gnomad4 OTH exome
AF:
0.00527
GnomAD4 genome
AF:
0.00458
AC:
698
AN:
152286
Hom.:
1
Cov.:
32
AF XY:
0.00422
AC XY:
314
AN XY:
74462
show subpopulations
Gnomad4 AFR
AF:
0.00166
Gnomad4 AMR
AF:
0.00288
Gnomad4 ASJ
AF:
0.000576
Gnomad4 EAS
AF:
0.000386
Gnomad4 SAS
AF:
0.00622
Gnomad4 FIN
AF:
0.00122
Gnomad4 NFE
AF:
0.00783
Gnomad4 OTH
AF:
0.00190
Alfa
AF:
0.00643
Hom.:
9
Bravo
AF:
0.00439
TwinsUK
AF:
0.00836
AC:
31
ALSPAC
AF:
0.0114
AC:
44
ESP6500AA
AF:
0.00204
AC:
9
ESP6500EA
AF:
0.00826
AC:
71
ExAC
AF:
0.00464
AC:
564
Asia WGS
AF:
0.000866
AC:
3
AN:
3478
EpiCase
AF:
0.00709
EpiControl
AF:
0.00848

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:11
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Benign:5
Benign, no assertion criteria providedclinical testingJoint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+-- -
Benign, no assertion criteria providedclinical testingLaboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)-- -
Benign, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Jun 16, 2017- -
Benign, criteria provided, single submitterclinical testingGeneDxJul 25, 2017This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Benign, criteria provided, single submitterclinical testingGenomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of PhiladelphiaNov 06, 2015- -
not provided Benign:3
Likely benign, criteria provided, single submitterclinical testingCenter for Pediatric Genomic Medicine, Children's Mercy Hospital and ClinicsMay 02, 2017- -
Likely benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenNov 01, 2024CLCN1: PP3, BS2 -
Benign, criteria provided, single submitterclinical testingAthena DiagnosticsFeb 16, 2018- -
Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Benign:2
Likely benign, criteria provided, single submitterresearchDepartment Of Human Genetics, Institute Of Clinical And Translational Research, Biomedical Research Center, Slovak Academy Of Sciences-The c.899G>A (p.(Arg300Gln)) variant was found in a heterozygous state in 2 Slovak patients with Myotonia congenita: the first one carried another 2 Likely Pathogenic variants: c.1231G>T and C2680C>T; while in the second one, no other Pathogenic or Likely pathogenic variants were found. GnomAD Exomes Version: 4.0 indicates the frequency of f = 0.00734. This variant has been reported in HGMD database CM940284. -
Benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 31, 2024- -
Congenital myotonia, autosomal recessive form Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingMayo Clinic Laboratories, Mayo ClinicSep 21, 2017- -
Batten-Turner congenital myopathy Benign:1
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaMar 06, 2018This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.17
BayesDel_addAF
Benign
0.0053
T
BayesDel_noAF
Pathogenic
0.24
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.81
.;D
Eigen
Uncertain
0.60
Eigen_PC
Uncertain
0.50
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.68
D
MetaRNN
Benign
0.017
T;T
MetaSVM
Uncertain
0.79
D
MutationAssessor
Uncertain
2.9
.;M
MutationTaster
Benign
1.0
D
PrimateAI
Pathogenic
0.84
D
PROVEAN
Uncertain
-3.7
.;D
REVEL
Pathogenic
0.86
Sift
Pathogenic
0.0
.;D
Sift4G
Uncertain
0.0030
.;D
Polyphen
1.0
.;D
Vest4
0.79
MVP
0.98
MPC
0.68
ClinPred
0.023
T
GERP RS
3.7
Varity_R
0.92
gMVP
0.77

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.15
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs118066140; hg19: chr7-143027910; COSMIC: COSV58368687; API