rs374764234

chr19-13312749-T-Achr19-13312749-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_001127222.2(CACNA1A):c.1588A>T(p.Met530Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M530V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.80

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 Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_001127222.2
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, CACNA1A
• BP4: Computational evidence support a benign effect (MetaRNN=0.17643714).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNA1A	NM_001127222.2	c.1588A>T	p.Met530Leu	missense_variant	12/47	ENST00000360228.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNA1A	ENST00000360228.11	c.1588A>T	p.Met530Leu	missense_variant	12/47	1	NM_001127222.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000888 AC: 2 AN: 225256 Hom.: 0 AF XY: 0.0000162 AC XY: 2 AN XY: 123142

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.0000190

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000122 AC: 1

ExAC AF: 0.0000166 AC: 2

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.29
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.10
Cadd	Benign	23
Dann	Benign	0.83
Eigen	Benign	-0.61
Eigen_PC	Benign	-0.38
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Uncertain	0.93	D;D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP	Uncertain	0.10	D
MetaRNN	Benign	0.18	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.38	D
MutationTaster	Benign	0.97	D;D;D
PrimateAI	Uncertain	0.72	T
Sift4G	Benign	1.0	T;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.35
MutPred		0.59		Loss of helix (P = 0.2271);.;Loss of helix (P = 0.2271);Loss of helix (P = 0.2271);Loss of helix (P = 0.2271);.;Loss of helix (P = 0.2271);Loss of helix (P = 0.2271);Loss of helix (P = 0.2271);Loss of helix (P = 0.2271);Loss of helix (P = 0.2271);.;Loss of helix (P = 0.2271);.;Loss of helix (P = 0.2271);
MVP		0.95
MPC		1.2
ClinPred		0.18	T
GERP RS		4.1
Varity_R		0.19
gMVP		0.75

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

Other links and lift over

dbSNP: rs374764234; hg19: chr19-13423563;