19-13455205-C-T

Variant names:

• chr19-13455205-C-T
• NM_001127222.2:c.301G>A

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5_Very_Strong

The NM_001127222.2(CACNA1A):​c.301G>A​(p.Glu101Lys) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E101Q) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.81

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 Pathogenic. Variant got 17 ACMG points.

• PM1: In a repeat I (size 278) in uniprot entity CAC1A_HUMAN there are 11 pathogenic changes around while only 1 benign (92%) in NM_001127222.2
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-13455205-C-G is described in Lovd as [Pathogenic].
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.887
• PP5: Variant 19-13455205-C-T is Pathogenic according to our data. Variant chr19-13455205-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1185925.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	ENST00000360228.11	NP_001120694.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1A	ENST00000360228.11	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	1	NM_001127222.2	ENSP00000353362.5
CACNA1A	ENST00000638029.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 48	5		ENSP00000489829.1
CACNA1A	ENST00000573710.7	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	5		ENSP00000460092.3
CACNA1A	ENST00000635727.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	5		ENSP00000490001.1
CACNA1A	ENST00000637769.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	1		ENSP00000489778.1
CACNA1A	ENST00000636012.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 46	5		ENSP00000490223.1
CACNA1A	ENST00000636389.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	5		ENSP00000489992.1
CACNA1A	ENST00000637432.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 48	5		ENSP00000490617.1
CACNA1A	ENST00000636549.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 48	5		ENSP00000490578.1
CACNA1A	ENST00000637927.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	5		ENSP00000489715.1
CACNA1A	ENST00000635895.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	5		ENSP00000490323.1
CACNA1A	ENST00000638009.2	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 47	1		ENSP00000489913.1
CACNA1A	ENST00000637276.1	c.301G>A	p.Glu101Lys	missense_variant	Exon 2 of 46	5		ENSP00000489777.1
CACNA1A	ENST00000637736.1	c.259-2190G>A		intron_variant	Intron 1 of 45	5		ENSP00000489861.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 25

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Sep 15, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid with lysine at codon 101 of the CACNA1A protein (p.Glu101Lys). The glutamic acid residue is highly conserved and there is a small physicochemical difference between glutamic acid and lysine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with CACNA1A-related conditions. ClinVar contains an entry for this variant (Variation ID: 1185925). 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. This variant disrupts the p.Glu101 amino acid residue in CACNA1A. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 27476654, 30185235). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

not provided Pathogenic:1

Aug 11, 2020

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	.;D;T;.;.;.;.;.;T;.;.;.;T;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.91	D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.39	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.41	D
MutationAssessor	Uncertain	2.6	.;M;.;.;M;.;M;.;.;.;.;M;.;.
PrimateAI	Pathogenic	0.93	D
PROVEAN	Uncertain	-3.2	.;D;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Pathogenic	0.76
Sift	Uncertain	0.0010	.;D;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Uncertain	0.014	D;D;.;.;.;.;.;.;.;.;D;.;.;.
Polyphen		1.0	.;D;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.90
MutPred		0.63		Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);Gain of methylation at E101 (P = 0.002);
MVP		0.89
MPC		1.8
ClinPred		0.99	D
GERP RS		5.0
Varity_R		0.73
gMVP		0.89

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr19-13566019;