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rs1555731992

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1_ModeratePM2PP3_StrongPP5_Moderate

The NM_001127222.2(CACNA1A):c.5941-2A>G variant causes a splice acceptor change. The variant allele was found at a frequency of 0.000000754 in 1,325,966 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 7.5e-7 ( 0 hom. )

Consequence

CACNA1A
NM_001127222.2 splice_acceptor

Scores

3
2
2
Splicing: ADA: 1.000
2

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 4.63
Variant links:
Genes affected
CACNA1A (HGNC:1388): (calcium voltage-gated channel subunit alpha1 A) Voltage-dependent calcium channels mediate the entry of calcium ions into excitable cells, and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, and gene expression. Calcium channels are multisubunit complexes composed of alpha-1, beta, alpha-2/delta, and gamma subunits. The channel activity is directed by the pore-forming alpha-1 subunit, whereas, the others act as auxiliary subunits regulating this activity. The distinctive properties of the calcium channel types are related primarily to the expression of a variety of alpha-1 isoforms, alpha-1A, B, C, D, E, and S. This gene encodes the alpha-1A subunit, which is predominantly expressed in neuronal tissue. Mutations in this gene are associated with 2 neurologic disorders, familial hemiplegic migraine and episodic ataxia 2. This gene also exhibits polymorphic variation due to (CAG)n-repeats. Multiple transcript variants encoding different isoforms have been found for this gene. In one set of transcript variants, the (CAG)n-repeats occur in the 3' UTR, and are not associated with any disease. But in another set of variants, an insertion extends the coding region to include the (CAG)n-repeats which encode a polyglutamine tract. Expansion of the (CAG)n-repeats from the normal 4-18 to 21-33 in the coding region is associated with spinocerebellar ataxia 6. [provided by RefSeq, Jul 2016]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PVS1
Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.014492754 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.7, offset of 24, new splice context is: ggacacccctcatgttccAGcgc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 19-13212742-T-C is Pathogenic according to our data. Variant chr19-13212742-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 522037.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
CACNA1ANM_001127222.2 linkuse as main transcriptc.5941-2A>G splice_acceptor_variant ENST00000360228.11

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
CACNA1AENST00000360228.11 linkuse as main transcriptc.5941-2A>G splice_acceptor_variant 1 NM_001127222.2 O00555-8

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
7.54e-7
AC:
1
AN:
1325966
Hom.:
0
Cov.:
30
AF XY:
0.00000155
AC XY:
1
AN XY:
647196
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
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:
9.62e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Inborn genetic diseases Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingAmbry GeneticsOct 16, 2023The c.5944-2A>G intronic variant results from an A to G substitution two nucleotides before coding exon 41 of the CACNA1A gene. Alterations that disrupt the canonical splice site are expected to result in aberrant splicing. The resulting transcript is predicted to be in-frame and is not expected to trigger nonsense-mediated mRNAdecay; however, direct evidence is unavailable. The exact functional effect of the altered amino acid sequence is unknown._x000D_ _x000D_ _x000D_ _x000D_ ; however, it is unlikely to be causative of CACNA1A-related spinocerebellar ataxia. This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. Based on the available evidence, this alteration is classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Benign
-0.20
Cadd
Pathogenic
34
Dann
Uncertain
0.98
Eigen
Pathogenic
0.88
Eigen_PC
Uncertain
0.65
FATHMM_MKL
Pathogenic
0.98
D
MutationTaster
Benign
1.0
D;D;D
GERP RS
4.5

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.89
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.71
Position offset: -26
DS_AL_spliceai
0.99
Position offset: -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.

Other links and lift over

dbSNP: rs1555731992; hg19: chr19-13323556; API