rs1555773757

Positions:

• chr19-13359733-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_001127222.2(CACNA1A):​c.851G>T​(p.Gly284Val) 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 pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 3.24

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 Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a topological_domain Extracellular (size 86) in uniprot entity CAC1A_HUMAN there are 6 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.874

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.851G>T	p.Gly284Val	missense_variant	6/47	ENST00000360228.11	NP_001120694.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CACNA1A	ENST00000360228.11	c.851G>T	p.Gly284Val	missense_variant	6/47	1	NM_001127222.2	ENSP00000353362

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1425388 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 705404

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Episodic ataxia type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

research

HudsonAlpha Institute for Biotechnology, HudsonAlpha Institute for Biotechnology

Apr 16, 2018

- -

Developmental and epileptic encephalopathy, 42 Uncertain:1

Uncertain significance, criteria provided, single submitter

research

HudsonAlpha Institute for Biotechnology, HudsonAlpha Institute for Biotechnology

Aug 09, 2021

ACMG codes:PM2, PP3 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.87
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.43
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	.;D;T;.;.;.;.;.;.;T;.;.;.;T;.
Eigen	Pathogenic	0.70
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.87	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.4	.;M;.;.;M;.;.;M;.;.;.;.;M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.73	T
PROVEAN	Pathogenic	-6.4	.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Pathogenic	0.83
Sift	Benign	0.054	.;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Benign	0.068	T;T;.;.;.;.;.;.;.;.;.;D;.;.;.
Polyphen		0.99	.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.75
MutPred		0.66		Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);.;Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);Loss of disorder (P = 0.0311);
MVP		0.95
MPC		2.5
ClinPred		0.98	D
GERP RS		5.3
Varity_R		0.61
gMVP		0.98

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: rs1555773757; hg19: chr19-13470547;