Genetic Variant CACNA1A:p.Gly918Gly (chr19-13298879-G-A) – ACMG Classification: Benign (-10 pts)

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_StrongBP6BP7BS2

The NM_001127222.2(CACNA1A):c.2754C>T(p.Gly918Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000054 in 1,592,958 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 Conflicting classifications of pathogenicity (no stars).

Frequency

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

Exomes 𝑓: 0.000058 ( 0 hom. )

Consequence

CACNA1A
NM_001127222.2 synonymous

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: -0.794

Publications

1 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:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -10 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.81).

BP6

Variant 19-13298879-G-A is Benign according to our data. Variant chr19-13298879-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 387665.

BP7

Synonymous conserved (PhyloP=-0.794 with no splicing effect.

BS2

High AC in GnomAdExome4 at 84 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001127222.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
CACNA1A	NM_001127222.2	MANE Select	c.2754C>T	p.Gly918Gly	synonymous	Exon 19 of 47	NP_001120694.1
CACNA1A	NM_001127221.2	MANE Plus Clinical	c.2757C>T	p.Gly919Gly	synonymous	Exon 19 of 47	NP_001120693.1
CACNA1A	NM_023035.3		c.2766C>T	p.Gly922Gly	synonymous	Exon 19 of 48	NP_075461.2

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
CACNA1A	ENST00000360228.11	TSL:1 MANE Select	c.2754C>T	p.Gly918Gly	synonymous	Exon 19 of 47	ENSP00000353362.5
CACNA1A	ENST00000638009.2	TSL:1 MANE Plus Clinical	c.2757C>T	p.Gly919Gly	synonymous	Exon 19 of 47	ENSP00000489913.1
CACNA1A	ENST00000638029.1	TSL:5	c.2766C>T	p.Gly922Gly	synonymous	Exon 19 of 48	ENSP00000489829.1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152136

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:

0.0000739

AC:

AN:

216464

AF XY:

0.0000497

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000238

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000307

Gnomad OTH exome

AF:

0.000912

GnomAD4 exome

AF:

0.0000583

AC:

AN:

1440822

Hom.:

Cov.:

AF XY:

0.0000516

AC XY:

AN XY:

716986

show subpopulations

African (AFR)

AF:

0.0000302

AC:

AN:

33060

American (AMR)

AF:

0.000271

AC:

AN:

44324

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25912

East Asian (EAS)

AF:

0.00

AC:

AN:

39370

South Asian (SAS)

AF:

0.00

AC:

AN:

85358

European-Finnish (FIN)

AF:

0.00

AC:

AN:

38074

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5366

European-Non Finnish (NFE)

AF:

0.0000604

AC:

AN:

1109426

Other (OTH)

AF:

0.0000667

AC:

AN:

59932

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.477

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:

0.0000131

AC:

AN:

152136

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74320

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41434

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5174

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68002

Other (OTH)

AF:

0.00

AC:

AN:

2092

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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000604

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Jul 13, 2016

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

A variant of uncertain significance has been identified in the CACNA1A gene. The c.2757 C>T variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The c.2757 C>T variant was not observed with any significant frequency in approximately 5,600 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project. This substitution occurs at a position that is not conserved. Several in-silico splice prediction models predict that c.2757 C>T creates a cryptic donor site which may supplant the natural donor site in exon 19 and lead to abnormal gene splicing. However, in the absence of RNA/functional studies, the actual effect of this sequence change is unknown. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant.

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

Benign:1

Dec 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.81

CADD

Benign

5.7

(source)

DANN

Benign

0.82

PhyloP100

-0.79

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over