chr19-13317306-C-T

Position:

chr19-13317306-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PP2PP3BS2

The NM_001127222.2(CACNA1A):c.1361G>A(p.Arg454Gln) variant causes a missense change. The variant allele was found at a frequency of 0.000091 in 1,605,006 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R454R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000097 ( 0 hom. )

Consequence

CACNA1A
NM_001127222.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:7B:1

Conservation

PhyloP100: 4.13

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CACNA1A. . Gene score misZ 5.7845 (greater than the threshold 3.09). Trascript score misZ 3.9354 (greater than threshold 3.09). GenCC has associacion of gene with 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, 0.768

BS2

High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNA1A	NM_001127222.2 linkuse as main transcript	c.1361G>A	p.Arg454Gln	missense_variant	11/47	ENST00000360228.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNA1A	ENST00000360228.11 linkuse as main transcript	c.1361G>A	p.Arg454Gln	missense_variant	11/47	1	NM_001127222.2		O00555-8

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152096

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000322

AC:

AN:

248320

Hom.:

AF XY:

0.0000445

AC XY:

AN XY:

134700

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000710

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000971

AC:

141

AN:

1452792

Hom.:

Cov.:

AF XY:

0.000111

AC XY:

AN XY:

720572

show subpopulations

Gnomad4 AFR exome

AF:

0.0000600

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000507

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000117

Gnomad4 OTH exome

AF:

0.000117

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74396

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000773

Hom.:

Bravo

AF:

0.0000869

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ExAC

AF:

0.0000248

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:7Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Aug 31, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Athena Diagnostics	Sep 26, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 21, 2023	Variant summary: CACNA1A c.1364G>A (p.Arg455Gln) results in a conservative amino acid change located in the ion transport domain (IPR005821) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.2e-05 in 248320 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1364G>A has been reported in the literature in the heterozygous state in an individual with symptoms consistent with Episodic Ataxia (Isaacs_2017). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 28540055). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Multiple submitters reported the variant with conflicting assessments, classifying the variant as either VUS (n=5), likely pathogenic (n=1), or likely benign (n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Aug 28, 2023	Reported in an individual with episodic ataxia in published literature (Isaacs et al., 2017).; In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32899500, 32116539, 28540055) -
Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2024	CACNA1A: PP2, PS4:Supporting -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 03, 2017	- -

Tip-toe gait

Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Practice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice Pomarino

Nov 08, 2021

Hereditary motor sensory neuropathy (HMSN), also known as Charcot-Marie-Tooth Disease (CMT), is the most commonly inherited peripheral polyneuropathy. It constitutes a group of inherited, progressive, motor and sensory peripheral nerve disorders with properties of demyelination, axonal degeneration, or both. It is classified by clinical characteristics, modes of inheritance, electrophysiologic features, metabolic defects, and specific gene markers. Our patients all walk on tiptoe, so they show similar symptoms. When we genetically test them with our toe walking panel, we find that around 90 per cent of them have a genetic variant that explains their toe walking. These can be assigned, for example, to the area of myopathies (such as variants of the COL6A3 gene), the area of hereditary neuropathies (such as variants of the KMT2C gene) or the area of metabolic diseases (such as variants of the PYGM gene). In a smaller group of patients with almost identical symptoms, no abnormality is found in the genes of our panel, but spastic paraplegia can be detected. In another small group of our toe walkers, no abnormalities can be detected in the genes analysed in our toe walking panel, nor do they suffer from spastic paraplegia, as is also the case with healthy children. In contrast to these, however, they show a tiptoe gait. These patients suffer from infantile cerebral palsy, in which toe walking can also be observed. -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 17, 2016

The p.R455Q variant (also known as c.1364G>A), located in coding exon 11 of the CACNA1A gene, results from a G to A substitution at nucleotide position 1364. The arginine at codon 455 is replaced by glutamine, an amino acid with highly similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6014 samples (12028 alleles) with coverage at this position. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on available evidence to date, the clinical significance of this variant remains unclear. -

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

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 11, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.80

BayesDel_addAF

Uncertain

0.071

BayesDel_noAF

Uncertain

0.050

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.086

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

Eigen

Pathogenic

0.76

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Uncertain

0.97

LIST_S2

Pathogenic

0.99

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

M_CAP

Uncertain

0.20

MetaRNN

Pathogenic

0.77

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

MetaSVM

Uncertain

0.50

MutationAssessor

Uncertain

2.4

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

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.54

PROVEAN

Uncertain

-3.8

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

REVEL

Uncertain

0.61

Sift

Uncertain

0.011

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

Sift4G

Uncertain

0.024

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

Vest4

0.54

MVP

0.91

MPC

2.2

ClinPred

0.78

GERP RS

5.8

Varity_R

0.41

gMVP

0.73

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over