NM_001127222.2:c.6775C>T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP3BS2

The NM_001127222.2(CACNA1A):c.6775C>T(p.Arg2259Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000021 in 1,574,614 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R2259Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

CACNA1A
NM_001127222.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 0.705

Publications

0 publications found

Variant links:

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

CACNA1A links:

ENSG00000300728 (HGNC:):

ENSG00000300728 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.84

BS2

High AC in GnomAdExome4 at 31 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA1A	NM_001127222.2 link	c.6775C>T	p.Arg2259Trp	missense_variant	Exon 46 of 47	ENST00000360228.11	NP_001120694.1	O00555-8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
CACNA1A	ENST00000360228.11 link	c.6775C>T	p.Arg2259Trp	missense_variant	Exon 46 of 47	1	NM_001127222.2	ENSP00000353362.5	O00555-8
CACNA1A	ENST00000638029.1 link	c.6793C>T	p.Arg2265Trp	missense_variant	Exon 47 of 48	5		ENSP00000489829.1	A0A087WW63
CACNA1A	ENST00000573710.7 link	c.6781C>T	p.Arg2261Trp	missense_variant	Exon 46 of 47	5		ENSP00000460092.3	A0A1C7CYY9
CACNA1A	ENST00000635727.1 link	c.6778C>T	p.Arg2260Trp	missense_variant	Exon 46 of 47	5		ENSP00000490001.1	A0A1B0GU81
CACNA1A	ENST00000637769.1 link	c.6778C>T	p.Arg2260Trp	missense_variant	Exon 46 of 47	1		ENSP00000489778.1	A0A1B0GTN7
CACNA1A	ENST00000636012.1 link	c.6742C>T	p.Arg2248Trp	missense_variant	Exon 45 of 46	5		ENSP00000490223.1	A0A1B0GUS3
CACNA1A	ENST00000637736.1 link	c.6637C>T	p.Arg2213Trp	missense_variant	Exon 45 of 46	5		ENSP00000489861.1	A0A1B0GTW2
CACNA1A	ENST00000636389.1 link	c.6778C>T	p.Arg2260Trp	missense_variant	Exon 46 of 47	5		ENSP00000489992.1	A0A1B0GU74
CACNA1A	ENST00000637432.1 link	c.6793C>T	p.Arg2265Trp	missense_variant	Exon 47 of 48	5		ENSP00000490617.1	O00555-2
CACNA1A	ENST00000636549.1 link	c.6784C>T	p.Arg2262Trp	missense_variant	Exon 47 of 48	5		ENSP00000490578.1	B5TYJ1
CACNA1A	ENST00000637927.1 link	c.6781C>T	p.Arg2261Trp	missense_variant	Exon 46 of 47	5		ENSP00000489715.1	A0A1B0GTI4
CACNA1A	ENST00000635895.1 link	c.6778C>T	p.Arg2260Trp	missense_variant	Exon 46 of 47	5		ENSP00000490323.1	A0A384DVW2
CACNA1A	ENST00000638009.2 link	c.6778C>T	p.Arg2260Trp	missense_variant	Exon 46 of 47	1		ENSP00000489913.1	O00555-3
CACNA1A	ENST00000637276.1 link	c.6742C>T	p.Arg2248Trp	missense_variant	Exon 45 of 46	5		ENSP00000489777.1	O00555-5
CACNA1A	ENST00000636768.2 link	n.*1041C>T		non_coding_transcript_exon_variant	Exon 44 of 45	5		ENSP00000490190.2	A0A1B0GUP3
CACNA1A	ENST00000713789.1 link	n.*1954C>T		non_coding_transcript_exon_variant	Exon 46 of 47			ENSP00000519091.1
CACNA1A	ENST00000636768.2 link	n.*1041C>T		3_prime_UTR_variant	Exon 44 of 45	5		ENSP00000490190.2	A0A1B0GUP3
CACNA1A	ENST00000713789.1 link	n.*1954C>T		3_prime_UTR_variant	Exon 46 of 47			ENSP00000519091.1

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152076

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000101

AC:

AN:

198976

AF XY:

0.0000180

show subpopulations

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000224

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000218

AC:

AN:

1422538

Hom.:

Cov.:

AF XY:

0.0000170

AC XY:

AN XY:

704816

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32946

American (AMR)

AF:

0.00

AC:

AN:

42576

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25618

East Asian (EAS)

AF:

0.00

AC:

AN:

38728

South Asian (SAS)

AF:

0.0000119

AC:

AN:

83930

European-Finnish (FIN)

AF:

0.00

AC:

AN:

36512

Middle Eastern (MID)

AF:

0.00

AC:

AN:

4114

European-Non Finnish (NFE)

AF:

0.0000264

AC:

AN:

1099142

Other (OTH)

AF:

0.0000170

AC:

AN:

58972

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.465

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152076

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74270

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41420

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5174

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

67968

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.450

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000174

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:3

May 24, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

May 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

CACNA1A: PP3 -

Mar 14, 2022

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Uncertain:1

Mar 13, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: CACNA1A c.6778C>T (p.Arg2260Trp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1e-05 in 198976 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.6778C>T in individuals affected with Epileptic Encephalopathy, Early Infantile, 42 and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 422310). Based on the evidence outlined above, the variant was classified as uncertain significance. -

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

Uncertain:1

Aug 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 2260 of the CACNA1A protein (p.Arg2260Trp). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 422310). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt CACNA1A protein function with a negative predictive value of 95%. 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. -

Inborn genetic diseases

Uncertain:1

Oct 19, 2017

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R2260W variant (also known as c.6778C>T), located in coding exon 46 of the CACNA1A gene, results from a C to T substitution at nucleotide position 6778. The arginine at codon 2260 is replaced by tryptophan, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

CACNA1A-related disorder

Uncertain:1

Dec 15, 2023

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

The CACNA1A c.6775C>T variant is predicted to result in the amino acid substitution p.Arg2259Trp. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0022% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/19-13319575-G-A). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.71

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Uncertain

0.10

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.17

.;.;T;.;.;.;.;.;T;.;.;T;.;.;.;T;.;.

Eigen

Benign

0.17

Eigen_PC

Benign

0.038

FATHMM_MKL

Benign

0.71

LIST_S2

Pathogenic

0.98

D;D;D;D;D;D;D;D;D;D;.;D;D;D;D;D;D;D

M_CAP

Pathogenic

0.85

MetaRNN

Pathogenic

0.84

D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Pathogenic

0.87

MutationAssessor

Uncertain

2.9

.;.;.;.;M;.;.;.;.;.;.;.;.;.;.;.;.;.

PhyloP100

0.70

PrimateAI

Pathogenic

0.96

PROVEAN

Pathogenic

-5.5

.;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.

REVEL

Uncertain

0.61

Sift

Uncertain

0.0010

.;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.

Sift4G

Uncertain

0.020

D;D;.;.;.;D;.;.;.;.;.;.;.;.;.;.;.;.

Vest4

0.67

MutPred

0.45

.;.;Loss of MoRF binding (P = 0.0921);Loss of MoRF binding (P = 0.0921);Loss of MoRF binding (P = 0.0921);.;.;Loss of MoRF binding (P = 0.0921);.;.;.;.;Loss of MoRF binding (P = 0.0921);.;.;.;.;.;

MVP

0.90

MPC

0.83

ClinPred

1.0

GERP RS

-0.20

Varity_R

0.26

gMVP

0.36

Mutation Taster

=43/57

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over