1-201078006-G-T

Variant names:

• chr1-201078006-G-T
• rs532351874
• NM_000069.3:c.1492C>A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_000069.3(CACNA1S):​c.1492C>A​(p.Arg498Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,220 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. R498C) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
• Consequence: CACNA1S NM_000069.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.11

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-201078005-C-T is described in Lovd as [Pathogenic].
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1S	NM_000069.3	c.1492C>A	p.Arg498Ser	missense_variant	Exon 11 of 44	ENST00000362061.4	NP_000060.2
CACNA1S	XM_005245478.4	c.1492C>A	p.Arg498Ser	missense_variant	Exon 11 of 43		XP_005245535.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1S	ENST00000362061.4	c.1492C>A	p.Arg498Ser	missense_variant	Exon 11 of 44	1	NM_000069.3	ENSP00000355192.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152220 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 35

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152220 Hom.: 0 Cov.: 31 AF XY: 0.0000134 AC XY: 1 AN XY: 74362

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Jun 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 498 of the CACNA1S protein (p.Arg498Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CACNA1S-related conditions. 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 with a positive predictive value of 80%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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

Jun 26, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with serine at codon 498 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 CACNA1S-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	36
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.72	D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.93	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.2	.;M
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-5.7	D;D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0010	D;D
Sift4G	Benign	0.088	T;T
Polyphen		1.0	.;D
Vest4		0.86
MutPred		0.66		Loss of MoRF binding (P = 0.0845);Loss of MoRF binding (P = 0.0845);
MVP		0.97
MPC		0.56
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.96
gMVP		0.81

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.95		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.95		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs532351874; hg19: chr1-201047134;