rs80338782
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM5PP3
The NM_000069.3(CACNA1S):c.3256C>T(p.Arg1086Cys) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,614,026 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 15/24 in silico tools predict a damaging outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1086H) has been classified as Uncertain significance.
Frequency
Consequence
NM_000069.3 missense, splice_region
Scores
Clinical Significance
Conservation
Publications
- congenital myopathy 18Inheritance: AD, AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- hypokalemic periodic paralysis, type 1Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
- malignant hyperthermia, susceptibility to, 5Inheritance: AD Classification: STRONG, MODERATE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics
- congenital myopathyInheritance: SD, AR, AD Classification: STRONG Submitted by: Illumina, Genomics England PanelApp
- hypokalemic periodic paralysisInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| CACNA1S | NM_000069.3 | c.3256C>T | p.Arg1086Cys | missense_variant, splice_region_variant | Exon 26 of 44 | ENST00000362061.4 | NP_000060.2 | |
| CACNA1S | XM_005245478.4 | c.3256C>T | p.Arg1086Cys | missense_variant, splice_region_variant | Exon 26 of 43 | XP_005245535.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| CACNA1S | ENST00000362061.4 | c.3256C>T | p.Arg1086Cys | missense_variant, splice_region_variant | Exon 26 of 44 | 1 | NM_000069.3 | ENSP00000355192.3 |
Frequencies
GnomAD3 genomes AF: 0.0000526 AC: 8AN: 152162Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000159 AC: 4AN: 251428 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000212 AC: 31AN: 1461864Hom.: 0 Cov.: 32 AF XY: 0.0000248 AC XY: 18AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000526 AC: 8AN: 152162Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4AN XY: 74328 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:3
Reported in a family with malignant hyperthermia, however, additional details were not provided (Jurkat-Rott et al., 2000); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 10590402, 25637381)
CACNA1S: PM5, PM2:Supporting, PP3, PP4
Hypokalemic periodic paralysis, type 1 Uncertain:2
The CACNA1S c.3256C>T variant is classified as VUS (PM2, PM5, PP3) The CACNA1S c.3256C>T variant is a single nucleotide change in exon 26/44 of the CACNA1S gene, which is predicted to change the amino acid arginine at position 1086 in the protein to cysteine. The variant is rare in population databases (gnomAD allele frequency = 0.0052%; 8 het and 0 hom in 152162 sequenced alleles; highest frequency = 0.0073%, Non-Finnish European population) (PM2_supporting). This variant is a novel missense change at an amino acid residue where a different missense change has been seen before (p.Arg1086His on ClinVar as drug response/pathogenic in Malignant hyperthermia c.3256C>A; p.Arg1086Ser on ClinVar as likely path) (PM5). Computational predictions support a deleterious effect on the gene or gene product (PP3). The variant has been reported in dbSNP (rs80338782) and in the HGMD database: CM003920. It has been reported as Uncertain significance by other diagnostic laboratories (ClinVar Variation ID: 21035). literature: the variant has been reported in a family with malignant hyperthermia (PMID:10590402).
not specified Uncertain:1
Variant summary: CACNA1S c.3256C>T (p.Arg1086Cys) results in a non-conservative amino acid change in the encoded protein sequence and alters the first nucleotide of exon 26 adjacent to the intron 25 splice acceptor site. Five of five in-silico tools predict a damaging effect of the variant on protein function. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.6e-05 in 251428 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.3256C>T has been reported in the literature in at least one individual affected with Malignant Hyperthermia Susceptibility (e.g. Jurkat-Rott_2000). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 25637381, 10590402). Four submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.
Malignant hyperthermia, susceptibility to, 5;C2749982:Thyrotoxic periodic paralysis, susceptibility to, 1;C3714580:Hypokalemic periodic paralysis, type 1;C5830283:Congenital myopathy 18 Uncertain:1
Hypokalemic periodic paralysis Uncertain:1
Congenital myopathy 18 Uncertain:1
Thyrotoxic periodic paralysis, susceptibility to, 1 Uncertain:1
Malignant hyperthermia, susceptibility to, 5;C3714580:Hypokalemic periodic paralysis, type 1 Uncertain:1
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 1086 of the CACNA1S protein (p.Arg1086Cys). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with malignant hyperthermia (PMID: 10590402). ClinVar contains an entry for this variant (Variation ID: 21035). 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. This variant disrupts the p.Arg1086 amino acid residue in CACNA1S. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9199552, 11260227, 12411788, 20431982). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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.
Malignant hyperthermia, susceptibility to, 5 Uncertain:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at