rs763772019

chr3-50376143-C-Achr3-50376143-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_006030.4(CACNA2D2):c.1672G>T(p.Val558Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,613,420 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. V558M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CACNA2D2 NM_006030.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.98

Genes affected

CACNA2D2 (HGNC:1400): (calcium voltage-gated channel auxiliary subunit alpha2delta 2) Calcium channels mediate the entry of calcium ions into the cell upon membrane polarization. This gene encodes the alpha-2/delta subunit of the voltage-dependent calcium channel complex. The complex consists of the main channel-forming subunit alpha-1, and auxiliary subunits alpha-2/delta, beta, and gamma. The auxiliary subunits function in the assembly and membrane localization of the complex, and modulate calcium currents and channel activation/inactivation kinetics. The subunit encoded by this gene undergoes post-translational cleavage to yield the extracellular alpha2 peptide and a membrane-anchored delta polypeptide. This subunit is a receptor for the antiepileptic drug, gabapentin. Mutations in this gene are associated with early infantile epileptic encephalopathy. Single nucleotide polymorphisms in this gene are correlated with increased sensitivity to opioid drugs. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Mar 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, CACNA2D2
• BP4: Computational evidence support a benign effect (MetaRNN=0.37472418).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNA2D2	NM_006030.4	c.1672G>T	p.Val558Leu	missense_variant	18/38	ENST00000424201.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNA2D2	ENST00000424201.7	c.1672G>T	p.Val558Leu	missense_variant	18/38	1	NM_006030.4	P4

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152210 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000483

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461210 Hom.: 0 Cov.: 35 AF XY: 0.00000275 AC XY: 2 AN XY: 726900

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152210 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74346

Gnomad4 AFR AF: 0.0000483

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: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 29, 2019

This sequence change replaces valine with leucine at codon 558 of the CACNA2D2 protein (p.Val558Leu). The valine residue is highly conserved and there is a small physicochemical difference between valine and leucine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with CACNA2D2-related disease. This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Uncertain	0.059	T
BayesDel_noAF	Benign	-0.15
Cadd	Uncertain	24
Dann	Uncertain	1.0
Eigen	Uncertain	0.33
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D
M_CAP	Benign	0.010	T
MetaRNN	Benign	0.37	T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.73	T
PROVEAN	Benign	-1.6	N;N;N;N;N;N
REVEL	Benign	0.21
Sift	Benign	0.080	T;T;T;T;T;T
Sift4G	Benign	0.079	T;T;T;T;T;T
Polyphen		0.74, 0.78	.;.;.;.;P;P
Vest4		0.58
MutPred		0.50		Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);.;Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);
MVP		0.48
MPC		0.53
ClinPred		0.93	D
GERP RS		4.3
Varity_R		0.24
gMVP		0.86

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

Other links and lift over

dbSNP: rs763772019; hg19: chr3-50413574;