1-201053539-G-A

Position:

• chr1-201053539-G-A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000069.3(CACNA1S):​c.3715C>T​(p.Arg1239Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,858 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging 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. R1239H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CACNA1S NM_000069.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.94

Genes affected

CACNA1S (HGNC:1397): (calcium voltage-gated channel subunit alpha1 S) This gene encodes one of the five subunits of the slowly inactivating L-type voltage-dependent calcium channel in skeletal muscle cells. Mutations in this gene have been associated with hypokalemic periodic paralysis, thyrotoxic periodic paralysis and malignant hyperthermia susceptibility. [provided by RefSeq, Jul 2008]

CACNA1S (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM1: In a transmembrane_region Helical; Name=S4 of repeat IV (size 18) in uniprot entity CAC1S_HUMAN there are 10 pathogenic changes around while only 0 benign (100%) in NM_000069.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-201053539-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 17624.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.96
• PP5: Variant 1-201053539-G-A is Pathogenic according to our data. Variant chr1-201053539-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 2166438.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CACNA1S	NM_000069.3	c.3715C>T	p.Arg1239Cys	missense_variant	30/44	ENST00000362061.4	NP_000060.2
CACNA1S	XM_005245478.4	c.3658C>T	p.Arg1220Cys	missense_variant	29/43		XP_005245535.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CACNA1S	ENST00000362061.4	c.3715C>T	p.Arg1239Cys	missense_variant	30/44	1	NM_000069.3	ENSP00000355192.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461858 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 727228

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Malignant hyperthermia, susceptibility to, 5;C3714580:Hypokalemic periodic paralysis, type 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 27, 2022

This variant has not been reported in the literature in individuals affected with CACNA1S-related conditions. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Arg1239 amino acid residue in CACNA1S. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7847370, 8004673, 15716625, 17418573, 18162704, 18229654, 19225109). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CACNA1S protein function. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 1239 of the CACNA1S protein (p.Arg1239Cys). -

Malignant hyperthermia, susceptibility to, 5 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Aug 15, 2023

This missense variant replaces arginine with cysteine at codon 1239 of the CACNA1S protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with autosomal dominant malignant hyperthermia in the literature, although it is associated with other phenotype(s) (ClinVar Variation ID: 2166438). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Due to insufficient evidence, this variant is classified as a Variant of Uncertain Significance for autosomal dominant malignant hyperthermia. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.96	D;D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	5.2	.;H
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-7.4	D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.96
MutPred		0.85		.;Loss of methylation at R1239 (P = 0.0171);
MVP		0.96
MPC		0.61
ClinPred		1.0	D
GERP RS		4.0
Varity_R		0.91
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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

Other links and lift over

dbSNP: rs28930069; hg19: chr1-201022667;