NM_000069.3:c.5049-2A>G

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 9P and 1B. PVS1PP5BS1_Supporting

The NM_000069.3(CACNA1S):c.5049-2A>G variant causes a splice acceptor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000788 in 1,610,682 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00048 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

CACNA1S
NM_000069.3 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

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

Conservation

PhyloP100: 2.28

Publications

0 publications found

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 Gene-Disease associations (from GenCC):

congenital myopathy 18
Inheritance: AD, AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
hypokalemic periodic paralysis, type 1
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
malignant hyperthermia, susceptibility to, 5
Inheritance: AD Classification: STRONG, MODERATE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics
congenital myopathy
Inheritance: SD, AR, AD Classification: STRONG Submitted by: Illumina, Genomics England PanelApp
hypokalemic periodic paralysis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

CACNA1S links:

ENSG00000234132 (HGNC:):

ENSG00000234132 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 4.7, offset of -17, new splice context is: gccttctctggttcacccAGcct. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PP5

Variant 1-201041591-T-C is Pathogenic according to our data. Variant chr1-201041591-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 541072.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000479 (73/152314) while in subpopulation AFR AF = 0.00166 (69/41564). AF 95% confidence interval is 0.00135. There are 0 homozygotes in GnomAd4. There are 34 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check. 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.5049-2A>G		splice_acceptor_variant, intron_variant	Intron 40 of 43	ENST00000362061.4	NP_000060.2
CACNA1S	XM_005245478.4 link	c.4992-2A>G		splice_acceptor_variant, intron_variant	Intron 39 of 42		XP_005245535.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1S	ENST00000362061.4 link	c.5049-2A>G		splice_acceptor_variant, intron_variant	Intron 40 of 43	1	NM_000069.3	ENSP00000355192.3

Frequencies

GnomAD3 genomes

AF:

0.000480

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00166

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.000479

GnomAD2 exomes

AF:

0.0000876

AC:

AN:

251240

AF XY:

0.0000368

show subpopulations

Gnomad AFR exome

AF:

0.00135

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS 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:

0.0000370

AC:

AN:

1458368

Hom.:

Cov.:

AF XY:

0.0000317

AC XY:

AN XY:

725810

show subpopulations

African (AFR)

AF:

0.00147

AC:

AN:

33400

American (AMR)

AF:

0.0000447

AC:

AN:

44718

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26108

East Asian (EAS)

AF:

0.00

AC:

AN:

39668

South Asian (SAS)

AF:

0.00

AC:

AN:

86170

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53408

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1108878

Other (OTH)

AF:

0.0000498

AC:

AN:

60256

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.453

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000479

AC:

AN:

152314

Hom.:

Cov.:

AF XY:

0.000457

AC XY:

AN XY:

74476

show subpopulations

African (AFR)

AF:

0.00166

AC:

AN:

41564

American (AMR)

AF:

0.000196

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68026

Other (OTH)

AF:

0.000474

AC:

AN:

2108

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.515

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000256

Hom.:

Bravo

AF:

0.000570

ESP6500AA

AF:

0.00113

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000988

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:2

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

Apr 17, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Pathogenic:1

Jul 02, 2025

GeneDx

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Has not been previously published as pathogenic or benign in association with CACNA1S-related disorder to our knowledge; This variant is associated with the following publications: (PMID: 30476936)

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

Pathogenic:1

Jan 08, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects an acceptor splice site in intron 40 of the CACNA1S gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CACNA1S are known to be pathogenic (PMID: 26247046, 28012042). This variant is present in population databases (rs148989517, gnomAD 0.1%). 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: 541072). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.

not specified

Uncertain:1

Nov 09, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: CACNA1S c.5049-2A>G is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a canonical 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 8.8e-05 in 251240 control chromosomes. The observed variant frequency is approximately 70-fold of the estimated maximal expected allele frequency for a pathogenic variant in CACNA1S causing Hypokalemic Periodic Paralysis phenotype (1.3e-06), strongly suggesting that the variant is benign. To our knowledge, no occurrence of c.5049-2A>G in individuals affected with Hypokalemic Periodic Paralysis and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One classified it as likely pathogenic and two as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.

Hypokalemic periodic paralysis, type 1

Uncertain:1

May 30, 2022

Mendelics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.25

BayesDel_noAF

Benign

-0.16

CADD

Pathogenic

(source)

DANN

Benign

0.97

DEOGEN2

Benign

0.0

.;.

Eigen

Pathogenic

0.74

Eigen_PC

Uncertain

0.50

FATHMM_MKL

Benign

0.73

LIST_S2

Benign

0.0

.;.

MetaRNN

Benign

0.0

.;.

MutationAssessor

Benign

0.0

.;.

PhyloP100

2.3

PROVEAN

Benign

0.0

.;.

REVEL

Benign

0.0

Sift

Pathogenic

0.0

.;.

Sift4G

Pathogenic

0.0

.;.

Vest4

0.0

GERP RS

4.5

Mutation Taster

=6/94

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

0.97

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.97

Position offset: -2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over