NM_001127222.2:c.2975A>G

Variant names:

• chr19-13298658-T-C
• rs16023
• NM_001127222.2:c.2975A>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.2975A>G​(p.Glu992Gly) 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. 13/21 in silico tools predict 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. E992V) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.84

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=0.31165236).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.2975A>G	p.Glu992Gly	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.2975A>G	p.Glu992Gly	missense_variant	Exon 19 of 47	1	NM_001127222.2	ENSP00000353362.5
CACNA1A	ENST00000638029.1	c.2987A>G	p.Glu996Gly	missense_variant	Exon 19 of 48	5		ENSP00000489829.1
CACNA1A	ENST00000573710.7	c.2981A>G	p.Glu994Gly	missense_variant	Exon 19 of 47	5		ENSP00000460092.3
CACNA1A	ENST00000635727.1	c.2978A>G	p.Glu993Gly	missense_variant	Exon 19 of 47	5		ENSP00000490001.1
CACNA1A	ENST00000637769.1	c.2978A>G	p.Glu993Gly	missense_variant	Exon 19 of 47	1		ENSP00000489778.1
CACNA1A	ENST00000636012.1	c.2978A>G	p.Glu993Gly	missense_variant	Exon 19 of 46	5		ENSP00000490223.1
CACNA1A	ENST00000637736.1	c.2837A>G	p.Glu946Gly	missense_variant	Exon 18 of 46	5		ENSP00000489861.1
CACNA1A	ENST00000636389.1	c.2978A>G	p.Glu993Gly	missense_variant	Exon 19 of 47	5		ENSP00000489992.1
CACNA1A	ENST00000637432.1	c.2987A>G	p.Glu996Gly	missense_variant	Exon 19 of 48	5		ENSP00000490617.1
CACNA1A	ENST00000636549.1	c.2978A>G	p.Glu993Gly	missense_variant	Exon 19 of 48	5		ENSP00000490578.1
CACNA1A	ENST00000637927.1	c.2981A>G	p.Glu994Gly	missense_variant	Exon 19 of 47	5		ENSP00000489715.1
CACNA1A	ENST00000635895.1	c.2978A>G	p.Glu993Gly	missense_variant	Exon 19 of 47	5		ENSP00000490323.1
CACNA1A	ENST00000638009.2	c.2978A>G	p.Glu993Gly	missense_variant	Exon 19 of 47	1		ENSP00000489913.1
CACNA1A	ENST00000637276.1	c.2978A>G	p.Glu993Gly	missense_variant	Exon 19 of 46	5		ENSP00000489777.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1351354 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 666448

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

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.079	D
BayesDel_noAF	Benign	-0.12
CADD	Benign	20
DANN	Benign	0.97
DEOGEN2	Benign	0.029	.;.;T;.;.;.;.;.;.;T;.;.;.;T;.
Eigen	Benign	-0.51
Eigen_PC	Benign	-0.43
FATHMM_MKL	Benign	0.19	N
LIST_S2	Benign	0.56	T;T;T;T;T;T;T;T;.;T;T;T;T;T;T
M_CAP	Pathogenic	0.91	D
MetaRNN	Benign	0.31	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.22	D
MutationAssessor	Benign	0.64	.;.;.;.;N;.;.;.;.;.;.;.;N;.;.
PrimateAI	Pathogenic	0.87	D
PROVEAN	Benign	-0.89	.;N;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Benign	0.27
Sift	Benign	0.16	.;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Benign	0.37	T;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.20
MutPred		0.29		.;.;Gain of MoRF binding (P = 0.0377);Gain of MoRF binding (P = 0.0377);Gain of MoRF binding (P = 0.0377);.;Gain of MoRF binding (P = 0.0377);.;.;Gain of MoRF binding (P = 0.0377);Gain of MoRF binding (P = 0.0377);.;Gain of MoRF binding (P = 0.0377);.;Gain of MoRF binding (P = 0.0377);
MVP		0.81
MPC		2.0
ClinPred		0.42	T
GERP RS		3.9
Varity_R		0.12
gMVP		0.40

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: rs16023; hg19: chr19-13409472;