rs748418783

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4BS2

The NM_001127222.2(CACNA1A):​c.2924G>T​(p.Arg975Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000015 in 1,466,374 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R975Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

CACNA1A
NM_001127222.2 missense

Scores

2
10
7

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 2.76

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.35452172).
BS2
High AC in GnomAdExome4 at 20 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CACNA1ANM_001127222.2 linkc.2924G>T p.Arg975Leu missense_variant Exon 19 of 47 ENST00000360228.11 NP_001120694.1 O00555-8

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CACNA1AENST00000360228.11 linkc.2924G>T p.Arg975Leu missense_variant Exon 19 of 47 1 NM_001127222.2 ENSP00000353362.5 O00555-8
CACNA1AENST00000638029.1 linkc.2936G>T p.Arg979Leu missense_variant Exon 19 of 48 5 ENSP00000489829.1 A0A087WW63
CACNA1AENST00000573710.7 linkc.2930G>T p.Arg977Leu missense_variant Exon 19 of 47 5 ENSP00000460092.3 A0A1C7CYY9
CACNA1AENST00000635727.1 linkc.2927G>T p.Arg976Leu missense_variant Exon 19 of 47 5 ENSP00000490001.1 A0A1B0GU81
CACNA1AENST00000637769.1 linkc.2927G>T p.Arg976Leu missense_variant Exon 19 of 47 1 ENSP00000489778.1 A0A1B0GTN7
CACNA1AENST00000636012.1 linkc.2927G>T p.Arg976Leu missense_variant Exon 19 of 46 5 ENSP00000490223.1 A0A1B0GUS3
CACNA1AENST00000637736.1 linkc.2786G>T p.Arg929Leu missense_variant Exon 18 of 46 5 ENSP00000489861.1 A0A1B0GTW2
CACNA1AENST00000636389.1 linkc.2927G>T p.Arg976Leu missense_variant Exon 19 of 47 5 ENSP00000489992.1 A0A1B0GU74
CACNA1AENST00000637432.1 linkc.2936G>T p.Arg979Leu missense_variant Exon 19 of 48 5 ENSP00000490617.1 O00555-2
CACNA1AENST00000636549.1 linkc.2927G>T p.Arg976Leu missense_variant Exon 19 of 48 5 ENSP00000490578.1 B5TYJ1
CACNA1AENST00000637927.1 linkc.2930G>T p.Arg977Leu missense_variant Exon 19 of 47 5 ENSP00000489715.1 A0A1B0GTI4
CACNA1AENST00000635895.1 linkc.2927G>T p.Arg976Leu missense_variant Exon 19 of 47 5 ENSP00000490323.1 A0A384DVW2
CACNA1AENST00000638009.2 linkc.2927G>T p.Arg976Leu missense_variant Exon 19 of 47 1 ENSP00000489913.1 O00555-3
CACNA1AENST00000637276.1 linkc.2927G>T p.Arg976Leu missense_variant Exon 19 of 46 5 ENSP00000489777.1 O00555-5
CACNA1AENST00000636768.2 linkn.2927G>T non_coding_transcript_exon_variant Exon 19 of 45 5 ENSP00000490190.2 A0A1B0GUP3
CACNA1AENST00000713789.1 linkn.2924G>T non_coding_transcript_exon_variant Exon 19 of 47 ENSP00000519091.1

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151896
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000656
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:
0.00
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.0000268
AC:
2
AN:
74750
AF XY:
0.0000232
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:
0.0000358
Gnomad OTH exome
AF:
0.000491
GnomAD4 exome
AF:
0.0000152
AC:
20
AN:
1314478
Hom.:
0
Cov.:
32
AF XY:
0.0000185
AC XY:
12
AN XY:
648014
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
25778
American (AMR)
AF:
0.0000462
AC:
1
AN:
21648
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
21812
East Asian (EAS)
AF:
0.00
AC:
0
AN:
29034
South Asian (SAS)
AF:
0.00
AC:
0
AN:
69290
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
42490
Middle Eastern (MID)
AF:
0.000611
AC:
3
AN:
4914
European-Non Finnish (NFE)
AF:
0.0000124
AC:
13
AN:
1045480
Other (OTH)
AF:
0.0000555
AC:
3
AN:
54032
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.505
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
2
AN:
151896
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74194
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41378
American (AMR)
AF:
0.0000656
AC:
1
AN:
15252
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5150
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10538
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
308
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67968
Other (OTH)
AF:
0.000479
AC:
1
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000496
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
May 02, 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.2927G>T (p.Arg976Leu) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The frequency data for this variant in gnomAD is considered unreliable, as metrics indicate poor data quality at this position. To our knowledge, no occurrence of c.2927G>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: 453002). 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
Jan 13, 2025
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 leucine, which is neutral and non-polar, at codon 976 of the CACNA1A protein (p.Arg976Leu). 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: 453002). 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
Aug 01, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.2927G>T (p.R976L) alteration is located in exon 19 (coding exon 19) of the CACNA1A gene. This alteration results from a G to T substitution at nucleotide position 2927, causing the arginine (R) at amino acid position 976 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Dec 12, 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 -

Spinocerebellar ataxia type 6;C1720416:Episodic ataxia type 2;C1832884:Migraine, familial hemiplegic, 1;C4310716:Developmental and epileptic encephalopathy, 42 Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.46
BayesDel_addAF
Uncertain
0.16
D
BayesDel_noAF
Uncertain
-0.010
CADD
Uncertain
23
DANN
Benign
0.97
DEOGEN2
Benign
0.063
.;.;T;.;.;.;.;.;.;T;.;.;.;T;.
Eigen
Benign
-0.036
Eigen_PC
Benign
-0.073
FATHMM_MKL
Uncertain
0.81
D
LIST_S2
Uncertain
0.95
D;D;D;D;D;D;D;D;.;D;D;D;D;D;D
M_CAP
Pathogenic
0.96
D
MetaRNN
Benign
0.35
T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM
Uncertain
0.40
D
MutationAssessor
Benign
1.6
.;.;.;.;L;.;.;.;.;.;.;.;L;.;.
PhyloP100
2.8
PrimateAI
Pathogenic
0.95
D
PROVEAN
Uncertain
-3.5
.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
REVEL
Uncertain
0.38
Sift
Uncertain
0.0090
.;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Sift4G
Uncertain
0.020
D;D;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4
0.35
MutPred
0.26
.;.;Loss of methylation at K973 (P = 0.0502);Loss of methylation at K973 (P = 0.0502);Loss of methylation at K973 (P = 0.0502);.;Loss of methylation at K973 (P = 0.0502);.;.;Loss of methylation at K973 (P = 0.0502);Loss of methylation at K973 (P = 0.0502);.;Loss of methylation at K973 (P = 0.0502);.;Loss of methylation at K973 (P = 0.0502);
MVP
0.90
MPC
1.9
ClinPred
0.32
T
GERP RS
4.1
Varity_R
0.34
gMVP
0.50
Mutation Taster
=80/20
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

Publications

Other links and lift over

dbSNP: rs748418783; hg19: chr19-13409523; API