rs781500916

chr1-201044347-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000069.3(CACNA1S):c.4778T>C(p.Met1593Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: CACNA1S NM_000069.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.59

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNA1S	NM_000069.3	c.4778T>C	p.Met1593Thr	missense_variant	39/44	ENST00000362061.4
CACNA1S	XM_005245478.4	c.4721T>C	p.Met1574Thr	missense_variant	38/43

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNA1S	ENST00000362061.4	c.4778T>C	p.Met1593Thr	missense_variant	39/44	1	NM_000069.3	P2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000315 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 28, 2018

This sequence change replaces methionine with threonine at codon 1593 of the CACNA1S protein (p.Met1593Thr). The methionine residue is moderately conserved and there is a moderate physicochemical difference between methionine and threonine. This variant is present in population databases (rs781500916, ExAC 0.01%). This variant has not been reported in the literature in individuals with CACNA1S-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
Cadd	Benign	23
Dann	Benign	0.86
DEOGEN2	Benign	0.0080	T;T
Eigen	Benign	-0.082
Eigen_PC	Benign	0.047
FATHMM_MKL	Benign	0.69	D
LIST_S2	Benign	0.80	T;T
M_CAP	Uncertain	0.094	D
MetaRNN	Uncertain	0.49	T;T
MetaSVM	Uncertain	0.32	D
MutationTaster	Benign	0.64	N;N
PrimateAI	Uncertain	0.64	T
PROVEAN	Benign	-0.21	N;N
REVEL	Uncertain	0.32
Sift	Benign	0.62	T;T
Sift4G	Benign	0.77	T;T
Polyphen		0.24	.;B
Vest4		0.65
MutPred		0.32		.;Gain of catalytic residue at M1588 (P = 0.0184);
MVP		0.95
MPC		0.13
ClinPred		0.28	T
GERP RS		5.0
Varity_R		0.13
gMVP		0.50

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs781500916; hg19: chr1-201013475;