dbSNP rs892742196: CACNA1S:c.3414+3A>T (chr1-201060655-T-A) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP5

The NM_000069.3(CACNA1S):c.3414+3A>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,066 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CACNA1S
NM_000069.3 splice_region, intron

Scores

Splicing: ADA: 0.9503

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:3

Conservation

PhyloP100: -0.247

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;

PP5

Variant 1-201060655-T-A is Pathogenic according to our data. Variant chr1-201060655-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 381082.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1S	NM_000069.3 link	c.3414+3A>T		splice_region_variant, intron_variant	Intron 26 of 43	ENST00000362061.4	NP_000060.2	Q13698
CACNA1S	XM_005245478.4 link	c.3414+3A>T		splice_region_variant, intron_variant	Intron 26 of 42		XP_005245535.1	B1ALM3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1S	ENST00000362061.4 link	c.3414+3A>T		splice_region_variant, intron_variant	Intron 26 of 43	1	NM_000069.3	ENSP00000355192.3		Q13698

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000795

AC:

AN:

251472

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135904

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461886

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

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:

8.99e-7

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74348

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000189

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

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

Pathogenic:1

Jun 03, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Pathogenic:1

Dec 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 26 of the CACNA1S gene. It does not directly change the encoded amino acid sequence of the CACNA1S protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has been observed in individuals with clinical features of autosomal recessive congenital myopathy (internal data). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 381082). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

CACNA1S-related disorder

Uncertain:1

May 26, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The CACNA1S c.3414+3A>T variant is predicted to interfere with splicing. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0056% of alleles in individuals of Latino descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not provided

Uncertain:1

Mar 24, 2025

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Has not been previously reported in peer-reviewed literature as pathogenic or benign to our knowledge. However, in an abstract by Al-Kharsan and Cardon, this variant was reported apparently homozygous in four patients from three families with severe congenital weakness (Al-Kharsan M and Cardon M. (2024) Neurology. 102 (7 supplement 1) https://www.neurology.org/doi/10.1212/WNL.0000000000205463).; In silico analysis is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: Al-Kharsan_2024_Abstract) -

Malignant hyperthermia, susceptibility to, 5

Uncertain:1

Aug 06, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes an A to T nucleotide substitution at the +3 position of intron 26 of the CACNA1S gene. 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: 381082). This variant has been identified in 3/282872 chromosomes 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

BayesDel_noAF

Benign

-0.38

CADD

Benign

DANN

Benign

0.90

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.95

dbscSNV1_RF

Pathogenic

0.76

SpliceAI score (max)

0.32

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.32

Position offset: 3

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