chr3-50364674-G-C

Position:

• chr3-50364674-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_006030.4(CACNA2D2):​c.3424C>G​(p.Arg1142Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000726 in 1,377,096 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict 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. R1142C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.3e-7 (0 hom.)
• Consequence: CACNA2D2 NM_006030.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.19

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]

LOC127898564 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CACNA2D2. . Gene score misZ 2.9999 (greater than the threshold 3.09). Trascript score misZ 3.123 (greater than threshold 3.09). GenCC has associacion of gene with cerebellar atrophy with seizures and variable developmental delay, complex neurodevelopmental disorder.
• BP4: Computational evidence support a benign effect (MetaRNN=0.11513448).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNA2D2	NM_006030.4	c.3424C>G	p.Arg1142Gly	missense_variant	38/38	ENST00000424201.7
LOC127898564	NR_183066.1	n.835-1623G>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNA2D2	ENST00000424201.7	c.3424C>G	p.Arg1142Gly	missense_variant	38/38	1	NM_006030.4	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.26e-7 AC: 1 AN: 1377096 Hom.: 0 Cov.: 32 AF XY: 0.00000148 AC XY: 1 AN XY: 677330

Gnomad4 AFR exome AF: 0.00

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: 9.36e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Labcorp Genetics (formerly Invitae), Labcorp

May 13, 2022

This variant has not been reported in the literature in individuals affected with CACNA2D2-related conditions. 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 1142 of the CACNA2D2 protein (p.Arg1142Gly). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.089
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.54
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.0070	.;T;.;.;.;T
Eigen	Benign	-0.34
Eigen_PC	Benign	-0.12
FATHMM_MKL	Benign	0.60	D
LIST_S2	Benign	0.59	T;T;T;T;T;T
M_CAP	Benign	0.083	D
MetaRNN	Benign	0.12	T;T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	.;.;.;.;.;N
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-0.47	N;N;N;N;N;N
REVEL	Benign	0.12
Sift	Pathogenic	0.0	D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D
Polyphen		0.0	.;.;.;.;B;B
Vest4		0.080
MutPred		0.26		Loss of stability (P = 0.0038);.;.;.;.;.;
MVP		0.043
MPC		1.0
ClinPred		0.53	D
GERP RS		4.7
Varity_R		0.25
gMVP		0.67

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: rs376300457; hg19: chr3-50402105;