rs121908241

Variant names:

• chr19-13299243-A-G
• rs121908241
• NM_001127222.2:c.2390T>C

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2 BP4 BS2

The NM_001127222.2(CACNA1A):​c.2390T>C​(p.Met797Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000686 in 1,456,832 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 (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000069 (0 hom.)
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 3.88

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_benign. Variant got -4 ACMG points.

• 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=0.2714457).
• BS2: High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.2390T>C	p.Met797Thr	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.2390T>C	p.Met797Thr	missense_variant	Exon 19 of 47	1	NM_001127222.2	ENSP00000353362.5
CACNA1A	ENST00000638029.1	c.2402T>C	p.Met801Thr	missense_variant	Exon 19 of 48	5		ENSP00000489829.1
CACNA1A	ENST00000573710.7	c.2396T>C	p.Met799Thr	missense_variant	Exon 19 of 47	5		ENSP00000460092.3
CACNA1A	ENST00000635727.1	c.2393T>C	p.Met798Thr	missense_variant	Exon 19 of 47	5		ENSP00000490001.1
CACNA1A	ENST00000637769.1	c.2393T>C	p.Met798Thr	missense_variant	Exon 19 of 47	1		ENSP00000489778.1
CACNA1A	ENST00000636012.1	c.2393T>C	p.Met798Thr	missense_variant	Exon 19 of 46	5		ENSP00000490223.1
CACNA1A	ENST00000637736.1	c.2252T>C	p.Met751Thr	missense_variant	Exon 18 of 46	5		ENSP00000489861.1
CACNA1A	ENST00000636389.1	c.2393T>C	p.Met798Thr	missense_variant	Exon 19 of 47	5		ENSP00000489992.1
CACNA1A	ENST00000637432.1	c.2402T>C	p.Met801Thr	missense_variant	Exon 19 of 48	5		ENSP00000490617.1
CACNA1A	ENST00000636549.1	c.2393T>C	p.Met798Thr	missense_variant	Exon 19 of 48	5		ENSP00000490578.1
CACNA1A	ENST00000637927.1	c.2396T>C	p.Met799Thr	missense_variant	Exon 19 of 47	5		ENSP00000489715.1
CACNA1A	ENST00000635895.1	c.2393T>C	p.Met798Thr	missense_variant	Exon 19 of 47	5		ENSP00000490323.1
CACNA1A	ENST00000638009.2	c.2393T>C	p.Met798Thr	missense_variant	Exon 19 of 47	1		ENSP00000489913.1
CACNA1A	ENST00000637276.1	c.2393T>C	p.Met798Thr	missense_variant	Exon 19 of 46	5		ENSP00000489777.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000407 AC: 1 AN: 245606 Hom.: 0 AF XY: 0.00000749 AC XY: 1 AN XY: 133568

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: 0.00000889

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000686 AC: 10 AN: 1456832 Hom.: 0 Cov.: 32 AF XY: 0.00000690 AC XY: 5 AN XY: 724960

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: 0.00000899

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Nov 07, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported previously in a patient with common migraine attacks and history of paroxysmal torticollis of infancy with mild ataxic gait noted during the dystonic episodes; the variant was also present in the patient's brother and mother who also had common migraine attacks (PMID: 20129625); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 32116539, 32899500, 20129625) -

Episodic ataxia type 2 Other:1

-

UniProtKB/Swiss-Prot

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.51
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Benign	19
DANN	Benign	0.60
DEOGEN2	Benign	0.057	.;.;T;.;.;.;.;.;.;T;.;.;.;T;.
Eigen	Benign	-0.64
Eigen_PC	Benign	-0.55
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP	Benign	0.068	D
MetaRNN	Benign	0.27	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.30	T
MutationAssessor	Benign	1.0	.;.;.;.;L;.;.;.;.;.;.;.;L;.;.
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-3.4	.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Uncertain	0.55
Sift	Benign	0.030	.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Benign	0.39	T;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.71
MutPred		0.27		.;.;Loss of stability (P = 0.0095);Loss of stability (P = 0.0095);Loss of stability (P = 0.0095);.;Loss of stability (P = 0.0095);.;.;Loss of stability (P = 0.0095);Loss of stability (P = 0.0095);.;Loss of stability (P = 0.0095);.;Loss of stability (P = 0.0095);
MVP		0.98
MPC		1.4
ClinPred		0.16	T
GERP RS		1.4
Varity_R		0.34
gMVP		0.62

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: rs121908241; hg19: chr19-13410057;