19-13298695-G-C

Variant names:

• chr19-13298695-G-C
• rs778978325
• NM_001127222.2:c.2938C>G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_001127222.2(CACNA1A):​c.2938C>G​(p.Arg980Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000774 in 1,291,526 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R980C) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.7e-7 (0 hom.)
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.37

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the CACNA1A gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 137 curated pathogenic missense variants (we use a threshold of 10). The gene has 132 curated benign missense variants. Gene score misZ: 5.7845 (above the threshold of 3.09). Trascript score misZ: 3.9354 (above the threshold of 3.09). GenCC associations: The gene is linked to 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=0.35987228).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.2938C>G	p.Arg980Gly	missense_variant	Exon 19 of 47	ENST00000360228.11	NP_001120694.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1A	ENST00000360228.11	c.2938C>G	p.Arg980Gly	missense_variant	Exon 19 of 47	1	NM_001127222.2	ENSP00000353362.5
CACNA1A	ENST00000638029.1	c.2950C>G	p.Arg984Gly	missense_variant	Exon 19 of 48	5		ENSP00000489829.1
CACNA1A	ENST00000573710.7	c.2944C>G	p.Arg982Gly	missense_variant	Exon 19 of 47	5		ENSP00000460092.3
CACNA1A	ENST00000635727.1	c.2941C>G	p.Arg981Gly	missense_variant	Exon 19 of 47	5		ENSP00000490001.1
CACNA1A	ENST00000637769.1	c.2941C>G	p.Arg981Gly	missense_variant	Exon 19 of 47	1		ENSP00000489778.1
CACNA1A	ENST00000636012.1	c.2941C>G	p.Arg981Gly	missense_variant	Exon 19 of 46	5		ENSP00000490223.1
CACNA1A	ENST00000637736.1	c.2800C>G	p.Arg934Gly	missense_variant	Exon 18 of 46	5		ENSP00000489861.1
CACNA1A	ENST00000636389.1	c.2941C>G	p.Arg981Gly	missense_variant	Exon 19 of 47	5		ENSP00000489992.1
CACNA1A	ENST00000637432.1	c.2950C>G	p.Arg984Gly	missense_variant	Exon 19 of 48	5		ENSP00000490617.1
CACNA1A	ENST00000636549.1	c.2941C>G	p.Arg981Gly	missense_variant	Exon 19 of 48	5		ENSP00000490578.1
CACNA1A	ENST00000637927.1	c.2944C>G	p.Arg982Gly	missense_variant	Exon 19 of 47	5		ENSP00000489715.1
CACNA1A	ENST00000635895.1	c.2941C>G	p.Arg981Gly	missense_variant	Exon 19 of 47	5		ENSP00000490323.1
CACNA1A	ENST00000638009.2	c.2941C>G	p.Arg981Gly	missense_variant	Exon 19 of 47	1		ENSP00000489913.1
CACNA1A	ENST00000637276.1	c.2941C>G	p.Arg981Gly	missense_variant	Exon 19 of 46	5		ENSP00000489777.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000165 AC: 1 AN: 60460 Hom.: 0 AF XY: 0.0000284 AC XY: 1 AN XY: 35200

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: 0.0000995

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 7.74e-7 AC: 1 AN: 1291526 Hom.: 0 Cov.: 32 AF XY: 0.00000157 AC XY: 1 AN XY: 636232

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: 0.0000156

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000396 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Jul 24, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Uncertain	0.038	T
BayesDel_noAF	Uncertain	0.020
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.057	.;.;T;.;.;.;.;.;.;T;.;.;.;T;.
Eigen	Benign	-0.30
Eigen_PC	Benign	-0.22
FATHMM_MKL	Benign	0.42	N
LIST_S2	Uncertain	0.94	D;D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.93	D
MetaRNN	Benign	0.36	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.048	T
MutationAssessor	Benign	1.6	.;.;.;.;L;.;.;.;.;.;.;.;L;.;.
PrimateAI	Pathogenic	0.94	D
PROVEAN	Uncertain	-2.6	.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.47
Sift	Uncertain	0.0060	.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.013	D;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.28
MutPred		0.21		.;.;Loss of MoRF binding (P = 0.0362);Loss of MoRF binding (P = 0.0362);Loss of MoRF binding (P = 0.0362);.;Loss of MoRF binding (P = 0.0362);.;.;Loss of MoRF binding (P = 0.0362);Loss of MoRF binding (P = 0.0362);.;Loss of MoRF binding (P = 0.0362);.;Loss of MoRF binding (P = 0.0362);
MVP		0.97
MPC		1.9
ClinPred		0.24	T
GERP RS		4.1
Varity_R		0.44
gMVP		0.54

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: rs778978325; hg19: chr19-13409509;