1-201078005-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2PP3_ModerateBS1_Supporting

The NM_000069.3(CACNA1S):c.1493G>A(p.Arg498His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000279 in 1,614,168 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic 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. R498C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00017 ( 0 hom., cov: 31)

Exomes 𝑓: 0.00029 ( 1 hom. )

Consequence

CACNA1S
NM_000069.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:1

Conservation

PhyloP100: 7.88

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.918

BS1

Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.000291 (425/1461836) while in subpopulation MID AF= 0.00208 (12/5768). AF 95% confidence interval is 0.0012. There are 1 homozygotes in gnomad4_exome. There are 208 alleles in male gnomad4_exome subpopulation. Median coverage is 35. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1S	NM_000069.3 link	c.1493G>A	p.Arg498His	missense_variant	Exon 11 of 44	ENST00000362061.4	NP_000060.2	Q13698
CACNA1S	XM_005245478.4 link	c.1493G>A	p.Arg498His	missense_variant	Exon 11 of 43		XP_005245535.1	B1ALM3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1S	ENST00000362061.4 link	c.1493G>A	p.Arg498His	missense_variant	Exon 11 of 44	1	NM_000069.3	ENSP00000355192.3		Q13698

Frequencies

GnomAD3 genomes

AF:

0.000171

AC:

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.000309

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000187

AC:

AN:

251488

Hom.:

AF XY:

0.000228

AC XY:

AN XY:

135920

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.000131

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000299

Gnomad OTH exome

AF:

0.000326

GnomAD4 exome

AF:

0.000291

AC:

425

AN:

1461836

Hom.:

Cov.:

AF XY:

0.000286

AC XY:

208

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000894

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000812

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000338

Gnomad4 OTH exome

AF:

0.000397

GnomAD4 genome

AF:

0.000171

AC:

AN:

152332

Hom.:

Cov.:

AF XY:

0.000175

AC XY:

AN XY:

74490

show subpopulations

Gnomad4 AFR

AF:

0.0000722

Gnomad4 AMR

AF:

0.0000653

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000309

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.0000170

Hom.:

Bravo

AF:

0.000208

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000778

AC:

ExAC

AF:

0.000239

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000654

EpiControl

AF:

0.000415

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Dec 02, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Apr 01, 2024	CACNA1S: PM2:Supporting -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Nov 07, 2024	Reported in an individual with exertional heat illness who harbored an additional variant in the CACNA1S gene and was not susceptible to malignant hyperthermia by in vitro contracture test (PMID: 25658027); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 37937776, 32054689, 25658027, 24195946, 36796140, 36292632) -

Malignant hyperthermia, susceptibility to, 5;C2749982:Thyrotoxic periodic paralysis, susceptibility to, 1;C3714580:Hypokalemic periodic paralysis, type 1;C5830283:Congenital myopathy 18

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

May 28, 2024

- -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 14, 2023

The c.1493G>A (p.R498H) alteration is located in exon 11 (coding exon 11) of the CACNA1S gene. This alteration results from a G to A substitution at nucleotide position 1493, causing the arginine (R) at amino acid position 498 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hypokalemic periodic paralysis, type 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 26, 2024

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 498 of the CACNA1S protein (p.Arg498His). This variant is present in population databases (rs150590855, gnomAD 0.03%). This missense change has been observed in individual(s) with clinical features of CACNA1S-related conditions (PMID: 25658027, 32054689). ClinVar contains an entry for this variant (Variation ID: 424926). 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%. 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

Uncertain

0.50

BayesDel_addAF

Pathogenic

0.27

BayesDel_noAF

Pathogenic

0.45

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.82

D;D

Eigen

Pathogenic

0.98

Eigen_PC

Pathogenic

0.87

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.98

D;D

M_CAP

Uncertain

0.26

MetaRNN

Pathogenic

0.92

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.5

.;M

PrimateAI

Uncertain

0.76

PROVEAN

Pathogenic

-4.7

D;D

REVEL

Pathogenic

0.93

Sift

Uncertain

0.0010

D;D

Sift4G

Benign

0.072

T;T

Polyphen

1.0

.;D

Vest4

0.82

MVP

0.97

MPC

0.59

ClinPred

0.56

GERP RS

4.8

Varity_R

0.94

gMVP

0.67

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over