chr19-13286881-G-T

Variant names:

• chr19-13286881-G-T
• rs775079932
• NM_001127222.2:c.3175C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001127222.2(CACNA1A):​c.3175C>A​(p.Pro1059Thr) 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. 15/22 in silico tools predict 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. P1059S) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CACNA1A NM_001127222.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.82
• Publications: 0 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: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.13855755).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1A	NM_001127222.2	c.3175C>A	p.Pro1059Thr	missense_variant	Exon 20 of 47	ENST00000360228.11	NP_001120694.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA1A	ENST00000360228.11	c.3175C>A	p.Pro1059Thr	missense_variant	Exon 20 of 47	1	NM_001127222.2	ENSP00000353362.5
CACNA1A	ENST00000638029.1	c.3187C>A	p.Pro1063Thr	missense_variant	Exon 20 of 48	5		ENSP00000489829.1
CACNA1A	ENST00000573710.7	c.3181C>A	p.Pro1061Thr	missense_variant	Exon 20 of 47	5		ENSP00000460092.3
CACNA1A	ENST00000635727.1	c.3178C>A	p.Pro1060Thr	missense_variant	Exon 20 of 47	5		ENSP00000490001.1
CACNA1A	ENST00000637769.1	c.3178C>A	p.Pro1060Thr	missense_variant	Exon 20 of 47	1		ENSP00000489778.1
CACNA1A	ENST00000636012.1	c.3178C>A	p.Pro1060Thr	missense_variant	Exon 20 of 46	5		ENSP00000490223.1
CACNA1A	ENST00000637736.1	c.3037C>A	p.Pro1013Thr	missense_variant	Exon 19 of 46	5		ENSP00000489861.1
CACNA1A	ENST00000636389.1	c.3178C>A	p.Pro1060Thr	missense_variant	Exon 20 of 47	5		ENSP00000489992.1
CACNA1A	ENST00000637432.1	c.3187C>A	p.Pro1063Thr	missense_variant	Exon 20 of 48	5		ENSP00000490617.1
CACNA1A	ENST00000636549.1	c.3178C>A	p.Pro1060Thr	missense_variant	Exon 20 of 48	5		ENSP00000490578.1
CACNA1A	ENST00000637927.1	c.3181C>A	p.Pro1061Thr	missense_variant	Exon 20 of 47	5		ENSP00000489715.1
CACNA1A	ENST00000635895.1	c.3178C>A	p.Pro1060Thr	missense_variant	Exon 20 of 47	5		ENSP00000490323.1
CACNA1A	ENST00000638009.2	c.3178C>A	p.Pro1060Thr	missense_variant	Exon 20 of 47	1		ENSP00000489913.1
CACNA1A	ENST00000637276.1	c.3178C>A	p.Pro1060Thr	missense_variant	Exon 20 of 46	5		ENSP00000489777.1
CACNA1A	ENST00000636768.2	n.3178C>A		non_coding_transcript_exon_variant	Exon 20 of 45	5		ENSP00000490190.2
CACNA1A	ENST00000713789.1	n.3175C>A		non_coding_transcript_exon_variant	Exon 20 of 47			ENSP00000519091.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

May 26, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals affected with CACNA1A-related conditions. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. 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 not expected to disrupt CACNA1A protein function. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1060 of the CACNA1A protein (p.Pro1060Thr). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.061
BayesDel_addAF	Uncertain	0.052	T
BayesDel_noAF	Benign	-0.16
CADD	Benign	21
DANN	Benign	0.94
DEOGEN2	Benign	0.013	.;.;T;.;.;.;.;.;.;T;.;.;.;T;.
Eigen	Benign	-0.20
Eigen_PC	Benign	0.00095
FATHMM_MKL	Benign	0.75	D
LIST_S2	Uncertain	0.90	D;D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.35	D
MetaRNN	Benign	0.14	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.23	T
MutationAssessor	Benign	1.8	.;.;.;.;L;.;.;.;.;.;.;.;L;.;.
PhyloP100		2.8
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-1.6	.;N;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL	Benign	0.25
Sift	Benign	0.54	.;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G	Benign	0.69	T;T;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.31
MutPred		0.26		.;.;Loss of catalytic residue at P1060 (P = 0.0028);Loss of catalytic residue at P1060 (P = 0.0028);Loss of catalytic residue at P1060 (P = 0.0028);.;Loss of catalytic residue at P1060 (P = 0.0028);.;.;Loss of catalytic residue at P1060 (P = 0.0028);Loss of catalytic residue at P1060 (P = 0.0028);.;Loss of catalytic residue at P1060 (P = 0.0028);.;Loss of catalytic residue at P1060 (P = 0.0028);
MVP		0.75
MPC		0.014
ClinPred		0.28	T
GERP RS		5.2
Varity_R		0.12
gMVP		0.35
Mutation Taster		=90/10	polymorphism

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

Other links and lift over

dbSNP: rs775079932; hg19: chr19-13397695;