rs797045032
Variant summary
Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PS1_ModeratePM1PM2PM5PP3PP5
The NM_000083.3(CLCN1):c.568_569delinsTC(p.Gly190Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G190R) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000083.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 10 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
CLCN1 | NM_000083.3 | c.568_569delinsTC | p.Gly190Ser | missense_variant | 5/23 | ENST00000343257.7 | |
CLCN1 | NR_046453.2 | n.670_671delinsTC | non_coding_transcript_exon_variant | 5/22 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
CLCN1 | ENST00000343257.7 | c.568_569delinsTC | p.Gly190Ser | missense_variant | 5/23 | 1 | NM_000083.3 | P4 |
Frequencies
GnomAD3 genomes ? Cov.: 33
GnomAD4 genome ? Cov.: 33
ClinVar
Submissions by phenotype
not provided Pathogenic:4Uncertain:1
Pathogenic, criteria provided, single submitter | clinical testing | Athena Diagnostics | Jan 11, 2022 | This variant is statistically more frequent in affected individuals than in the general population and/or healthy controls and therefore is consistent with pathogenicity (http://gnomad.broadinstitute.org). This variant has been reported in multiple families with autosomal recessive myotonia congenita (PMID: 19697366, 21221019, 22921319, 23113340), however, it has also been reported in individuals with autosomal dominant myotonia congenita (PMID: 23113340, 19697366, 22921319). At least one other missense variant at this codon is considered to be pathogenic or likely pathogenic, suggesting this variant may also cause disease. Assessment of experimental evidence suggests this variant results in abnormal protein function. This variant was shown to impair channel function by reducing permeability, current density and affecting channel deactivation properties (PMID: 22521272, 23933576). - |
Uncertain significance, criteria provided, single submitter | clinical testing | Eurofins Ntd Llc (ga) | Jan 13, 2017 | - - |
Pathogenic, criteria provided, single submitter | clinical testing | Revvity Omics, Revvity | Aug 17, 2023 | - - |
Pathogenic, criteria provided, single submitter | clinical testing | CeGaT Center for Human Genetics Tuebingen | Jul 01, 2021 | - - |
Pathogenic, criteria provided, single submitter | clinical testing | GeneDx | Dec 03, 2021 | Published electrophysiological studies in HEK293 cells showed a dramatic positive shift in voltage-dependent activation and highly reduced chloride currents (Desaphy et al., 2013); Not observed in large population cohorts (Lek et al., 2016); In silico analysis supports a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26633545, 23739125, 32117024, 32664137, 23933576, 22921319, 23113340, 24349310, 19697366, 22521272, 29606556, 32558419, 33013670, 32655465, 29809153) - |
Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Pathogenic:2
Likely pathogenic, criteria provided, single submitter | research | Department Of Human Genetics, Institute Of Clinical And Translational Research, Biomedical Research Center, Slovak Academy Of Sciences | - | The c.568_569delinsTC (p.(Gly190Ser)) variant was found in a heterozygous state in 1 Slovak patient with Myotonia congenita. No other Pathogenic or Likely pathogenic variants were found in this individual. According to PMID: 26007199, this variant is found in the highly conserved ClC-1 helix D motif, which plays a critical role in the chloride ion pathway. This variant has been reported in multiple families with autosomal recessive myotonia congenita (PMID: 19697366, 21221019, 22921319, 23113340), however, it has also been reported in individuals with autosomal dominant myotonia congenita (PMID: 23113340, 19697366, 22921319). As shown in PMID: 23933576, this variant in the heterozygous state manifests as asymptomatic or with only mild manifestations. - |
Pathogenic, criteria provided, single submitter | clinical testing | Invitae | Nov 05, 2023 | This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 190 of the CLCN1 protein (p.Gly190Ser). This variant is present in population databases (rs797045032, gnomAD 0.004%). This missense change has been observed in individuals with autosomal dominant and autosomal recessive myotonia congenita (PMID: 19697366, 21221019, 22521272, 22921319, 23739125, 24349310, 26007199). It has also been observed to segregate with disease in related individuals; in the heterozygous state this variant was reported to be incompletely penetrant and in the homozygous state it was reported to cause a more severe phenotype (PMID: 19697366, 22921319). ClinVar contains an entry for this variant (Variation ID: 209139). 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 disruptive. Experimental studies have shown that this missense change affects CLCN1 function (PMID: 22521272, 23933576). For these reasons, this variant has been classified as Pathogenic. - |
Congenital myotonia, autosomal recessive form Pathogenic:2
Likely pathogenic, criteria provided, single submitter | clinical testing | Baylor Genetics | Nov 26, 2013 | Likely pathogenicity based on finding it once in our laboratory with a known pathogenic missense variant (F167L; phase unknown) in a 46-year-old male with heart arrhythmia, hypertrophic cardiomyopathy, neuromuscular disease, EMG evidence of myopathy with myotonic discharges and mild length-dependent neuropathy, poor balance, short stature, scoliosis, small hands. - |
Pathogenic, criteria provided, single submitter | clinical testing | Women's Health and Genetics/Laboratory Corporation of America, LabCorp | Mar 26, 2024 | Variant summary: CLCN1 c.568_569delinsTC (p.Gly190Ser) results in a non-conservative amino acid change in the encoded protein sequence. Four of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4.4e-05 in 251480 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in CLCN1 causing Congenital Myotonia, Autosomal Recessive Form (4.4e-05 vs ND), allowing no conclusion about variant significance. c.568_569delinsTC has been reported in the literature in multiple individuals affected with Congenital Myotonia, Autosomal Recessive Form. These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity. ClinVar contains an entry for this variant (Variation ID: 209139). Based on the evidence outlined above, the variant was classified as pathogenic. - |
Headache;C0026837:Rigidity;C0027051:Myocardial infarction;C0042571:Vertigo;C4022169:EMG: myotonic discharges;C4022683:Myotonia of the upper limb Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Centre for Mendelian Genomics, University Medical Centre Ljubljana | Jan 01, 2017 | - - |
Congenital myotonia, autosomal dominant form Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | MGZ Medical Genetics Center | Sep 27, 2021 | - - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at