rs1553249775

Positions:

• chr1-201059272-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000069.3(CACNA1S):​c.3442C>T​(p.His1148Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign 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. H1148R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CACNA1S NM_000069.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.377

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.086915225).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNA1S	NM_000069.3	c.3442C>T	p.His1148Tyr	missense_variant	27/44	ENST00000362061.4
CACNA1S	XM_005245478.4	c.3442C>T	p.His1148Tyr	missense_variant	27/43

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNA1S	ENST00000362061.4	c.3442C>T	p.His1148Tyr	missense_variant	27/44	1	NM_000069.3	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 17, 2021

This sequence change replaces histidine, which is basic and polar, with tyrosine, which is neutral and polar, at codon 1148 of the CACNA1S protein (p.His1148Tyr). 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. ClinVar contains an entry for this variant (Variation ID: 473987). 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 not expected to disrupt CACNA1S protein function. 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

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Dec 18, 2023

This missense variant replaces histidine with tyrosine at codon 1148 of the CACNA1S protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with malignant hyperthermia 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	Benign	0.097
BayesDel_addAF	Uncertain	0.085	D
BayesDel_noAF	Benign	-0.12
CADD	Benign	17
DANN	Benign	0.87
DEOGEN2	Benign	0.27	T;T
Eigen	Benign	-0.45
Eigen_PC	Benign	-0.24
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Benign	0.39	T;T
M_CAP	Benign	0.032	D
MetaRNN	Benign	0.087	T;T
MetaSVM	Uncertain	0.098	D
MutationTaster	Benign	0.94	D;D
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-0.050	N;N
REVEL	Uncertain	0.34
Sift	Benign	0.34	T;T
Sift4G	Benign	0.11	T;T
Polyphen		0.0020	.;B
Vest4		0.15
MutPred		0.27		Loss of disorder (P = 0.0475);Loss of disorder (P = 0.0475);
MVP		0.86
MPC		0.12
ClinPred		0.51	D
GERP RS		3.8
Varity_R		0.10
gMVP		0.66

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: rs1553249775; hg19: chr1-201028400;