rs375210532

Positions:

• chr19-13317133-C-G
• chr19-13317133-C-T

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.1534G>C​(p.Glu512Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000275 in 1,454,694 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.33

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 repeat II (size 244) in uniprot entity CAC1A_HUMAN there are 11 pathogenic changes around while only 0 benign (100%) in NM_001127222.2
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CACNA1A. . Gene score misZ 5.7845 (greater than the threshold 3.09). Trascript score misZ 3.9354 (greater than threshold 3.09). GenCC has associacion of gene with benign paroxysmal torticollis of infancy, developmental and epileptic encephalopathy, 42, undetermined early-onset epileptic encephalopathy, episodic ataxia type 2, familial or sporadic hemiplegic migraine, spinocerebellar ataxia type 6, Lennox-Gastaut syndrome, migraine, familial hemiplegic, 1.
• BP4: Computational evidence support a benign effect (MetaRNN=0.17462322).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.1534G>C	p.Glu512Gln	missense_variant	11/47	ENST00000360228.11	NP_001120694.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CACNA1A	ENST00000360228.11	c.1534G>C	p.Glu512Gln	missense_variant	11/47	1	NM_001127222.2	ENSP00000353362

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000275 AC: 4 AN: 1454694 Hom.: 0 Cov.: 31 AF XY: 0.00000277 AC XY: 2 AN XY: 722140

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: 0.00000271

Gnomad4 OTH exome AF: 0.0000167

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 21, 2019

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with CACNA1A-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamic acid with glutamine at codon 513 of the CACNA1A protein (p.Glu513Gln). The glutamic acid residue is moderately conserved and there is a small physicochemical difference between glutamic acid and glutamine. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Dec 04, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Uncertain	0.015	T
BayesDel_noAF	Benign	-0.22
CADD	Uncertain	24
DANN	Benign	0.96
DEOGEN2	Benign	0.014	.;.;T;.;.;.;.;.;.;T;.;.;.;T;.
Eigen	Benign	-0.46
Eigen_PC	Benign	-0.27
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Uncertain	0.91	D;D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP	Benign	0.050	D
MetaRNN	Benign	0.17	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.30	T
MutationAssessor	Benign	0.79	.;.;.;.;N;.;.;N;.;.;.;.;N;.;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-1.7	.;N;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.31
Sift	Benign	0.80	.;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Benign	0.65	T;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.25
MutPred		0.42		Loss of helix (P = 0.1299);.;Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);.;Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);.;Loss of helix (P = 0.1299);.;Loss of helix (P = 0.1299);
MVP		0.81
MPC		1.8
ClinPred		0.38	T
GERP RS		3.8
Varity_R		0.16
gMVP		0.56

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: rs375210532; hg19: chr19-13427947;