rs121908222

Variant names:

• chr19-13371735-C-T
• rs121908222
• NM_001127222.2:c.584G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PP3_Strong PP5_Moderate

The NM_001127222.2(CACNA1A):​c.584G>A​(p.Arg195Lys) variant causes a missense change involving the alteration of a 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 Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 7.73
• Publications: 7 publications found

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]

CACNA1A Gene-Disease associations (from GenCC):

• episodic ataxia type 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Illumina
• developmental and epileptic encephalopathy, 42

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• migraine, familial hemiplegic, 1

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• spinocerebellar ataxia type 6

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet
• benign paroxysmal torticollis of infancy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial or sporadic hemiplegic migraine

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Lennox-Gastaut syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_001127222.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.942
• PP5: Variant 19-13371735-C-T is Pathogenic according to our data. Variant chr19-13371735-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 68439.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	ENST00000360228.11	NP_001120694.1
CACNA1A	NM_001127221.2	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	ENST00000638009.2	NP_001120693.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1A	ENST00000360228.11	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	1	NM_001127222.2	ENSP00000353362.5
CACNA1A	ENST00000638009.2	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	1	NM_001127221.2	ENSP00000489913.1
CACNA1A	ENST00000638029.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 48	5		ENSP00000489829.1
CACNA1A	ENST00000573710.7	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	5		ENSP00000460092.3
CACNA1A	ENST00000635727.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	5		ENSP00000490001.1
CACNA1A	ENST00000637769.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	1		ENSP00000489778.1
CACNA1A	ENST00000636012.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 46	5		ENSP00000490223.1
CACNA1A	ENST00000637736.1	c.443G>A	p.Arg148Lys	missense_variant	Exon 3 of 46	5		ENSP00000489861.1
CACNA1A	ENST00000636389.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	5		ENSP00000489992.1
CACNA1A	ENST00000637432.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 48	5		ENSP00000490617.1
CACNA1A	ENST00000636549.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 48	5		ENSP00000490578.1
CACNA1A	ENST00000637927.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	5		ENSP00000489715.1
CACNA1A	ENST00000635895.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 47	5		ENSP00000490323.1
CACNA1A	ENST00000637276.1	c.584G>A	p.Arg195Lys	missense_variant	Exon 4 of 46	5		ENSP00000489777.1
CACNA1A	ENST00000636768.2	n.584G>A		non_coding_transcript_exon_variant	Exon 4 of 45	5		ENSP00000490190.2
CACNA1A	ENST00000713789.1	n.584G>A		non_coding_transcript_exon_variant	Exon 4 of 47			ENSP00000519091.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Aug 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CACNA1A protein function. ClinVar contains an entry for this variant (Variation ID: 68439). This missense change has been observed in individual(s) with familial hemiplegic migraine (PMID: 11439943). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 195 of the CACNA1A protein (p.Arg195Lys). -

Migraine, familial hemiplegic, 1 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	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.95	.;D;T;.;.;.;.;.;.;T;.;.;.;T;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.76	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	.;H;.;.;H;.;.;H;.;.;.;.;H;.;.
PhyloP100		7.7
PrimateAI	Pathogenic	0.86	D
PROVEAN	Uncertain	-2.4	.;N;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0010	.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.0030	D;D;.;.;.;.;.;.;.;.;.;D;.;.;.
Polyphen		0.99	.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.81
MutPred		0.79		Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);.;Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);Loss of methylation at R195 (P = 0.0339);
MVP		0.99
MPC		1.8
ClinPred		0.99	D
GERP RS		4.9
Varity_R		0.83
gMVP		1.0
Mutation Taster		=7/93	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs121908222; hg19: chr19-13482549;