3-50434354-C-T

Variant names:

• chr3-50434354-C-T
• rs552824990
• NM_006030.4:c.364G>A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_006030.4(CACNA2D2):​c.364G>A​(p.Asp122Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,152 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: CACNA2D2 NM_006030.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.50

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CACNA2D2	NM_006030.4	c.364G>A	p.Asp122Asn	missense_variant	Exon 3 of 38	ENST00000424201.7	NP_006021.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CACNA2D2	ENST00000424201.7	c.364G>A	p.Asp122Asn	missense_variant	Exon 3 of 38	1	NM_006030.4	ENSP00000390329.2
CACNA2D2	ENST00000423994.6	c.364G>A	p.Asp122Asn	missense_variant	Exon 3 of 39	5		ENSP00000407393.2
CACNA2D2	ENST00000266039.7	c.364G>A	p.Asp122Asn	missense_variant	Exon 3 of 38	1		ENSP00000266039.3
CACNA2D2	ENST00000360963.7	c.157G>A	p.Asp53Asn	missense_variant	Exon 3 of 38	1		ENSP00000354228.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152152 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152152 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74314

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: 0.0000147

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

Mar 26, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid with asparagine at codon 122 of the CACNA2D2 protein (p.Asp122Asn). The aspartic acid residue is moderately conserved and there is a small physicochemical difference between aspartic acid and asparagine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with CACNA2D2-related conditions. 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 (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.55
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.019	.;T;.;.;.;T
Eigen	Benign	0.047
Eigen_PC	Uncertain	0.22
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.94	D;D;D;D;D;D
M_CAP	Benign	0.0071	T
MetaRNN	Uncertain	0.45	T;T;T;T;T;T
MetaSVM	Benign	-0.95	T
MutationAssessor	Benign	1.1	.;.;L;.;L;L
PrimateAI	Uncertain	0.69	T
PROVEAN	Benign	-0.96	N;N;N;N;N;N
REVEL	Benign	0.074
Sift	Benign	0.52	T;T;T;T;T;T
Sift4G	Benign	0.47	T;T;T;T;T;T
Polyphen		0.14, 0.089	.;.;.;.;B;B
Vest4		0.72
MutPred		0.35		Gain of MoRF binding (P = 0.0365);Gain of MoRF binding (P = 0.0365);Gain of MoRF binding (P = 0.0365);.;Gain of MoRF binding (P = 0.0365);Gain of MoRF binding (P = 0.0365);
MVP		0.068
MPC		0.62
ClinPred		0.92	D
GERP RS		4.9
Varity_R		0.16
gMVP		0.49

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

Other links and lift over

dbSNP: rs552824990; hg19: chr3-50471785;