rs1555762908

Variant names:

• chr19-13317227-GC-G
• rs1555762908
• NM_001127222.2:c.1439delG

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001127222.2(CACNA1A):​c.1439delG​(p.Arg480ProfsTer17) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CACNA1A NM_001127222.2 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.85

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-13317227-GC-G is Pathogenic according to our data. Variant chr19-13317227-GC-G is described in ClinVar as [Pathogenic]. Clinvar id is 476235.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.1439delG	p.Arg480ProfsTer17	frameshift_variant	Exon 11 of 47	ENST00000360228.11	NP_001120694.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1A	ENST00000360228.11	c.1439delG	p.Arg480ProfsTer17	frameshift_variant	Exon 11 of 47	1	NM_001127222.2	ENSP00000353362.5
CACNA1A	ENST00000638029.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 48	5		ENSP00000489829.1
CACNA1A	ENST00000573710.7	c.1445delG	p.Arg482ProfsTer17	frameshift_variant	Exon 11 of 47	5		ENSP00000460092.3
CACNA1A	ENST00000635727.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 47	5		ENSP00000490001.1
CACNA1A	ENST00000637769.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 47	1		ENSP00000489778.1
CACNA1A	ENST00000636012.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 46	5		ENSP00000490223.1
CACNA1A	ENST00000637736.1	c.1301delG	p.Arg434ProfsTer17	frameshift_variant	Exon 10 of 46	5		ENSP00000489861.1
CACNA1A	ENST00000636389.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 47	5		ENSP00000489992.1
CACNA1A	ENST00000637432.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 48	5		ENSP00000490617.1
CACNA1A	ENST00000636549.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 48	5		ENSP00000490578.1
CACNA1A	ENST00000637927.1	c.1445delG	p.Arg482ProfsTer17	frameshift_variant	Exon 11 of 47	5		ENSP00000489715.1
CACNA1A	ENST00000635895.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 47	5		ENSP00000490323.1
CACNA1A	ENST00000638009.2	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 47	1		ENSP00000489913.1
CACNA1A	ENST00000637276.1	c.1442delG	p.Arg481ProfsTer17	frameshift_variant	Exon 11 of 46	5		ENSP00000489777.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Episodic ataxia type 2;C4310716:Developmental and epileptic encephalopathy, 42 Pathogenic:1

Mar 13, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg481Profs*17) in the CACNA1A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CACNA1A are known to be pathogenic (PMID: 10371528, 19486177, 25735478, 27250579). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CACNA1A-related conditions. ClinVar contains an entry for this variant (Variation ID: 476235). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

May 16, 2017

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

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: rs1555762908; hg19: chr19-13428041;