3-50375704-C-T

Variant names:

• chr3-50375704-C-T
• rs371214569
• NM_006030.4:c.1847G>A

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_006030.4(CACNA2D2):​c.1847G>A​(p.Arg616Lys) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000363 in 1,461,084 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. R616R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000036 (0 hom.)
• Consequence: CACNA2D2 NM_006030.4 missense, splice_region
• Scores: Splicing: ADA: 0.4407
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.70
• Publications: 0 publications found

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]

CACNA2D2 Gene-Disease associations (from GenCC):

• cerebellar atrophy with seizures and variable developmental delay

  Inheritance: AR Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• complex neurodevelopmental disorder

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen

ENSG00000303671 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.372585).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006030.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CACNA2D2	NM_006030.4	MANE Select	c.1847G>A	p.Arg616Lys	missense splice_region	Exon 21 of 38	NP_006021.2
	CACNA2D2	NM_001174051.3		c.1847G>A	p.Arg616Lys	missense splice_region	Exon 21 of 39	NP_001167522.1
	CACNA2D2	NM_001005505.3		c.1847G>A	p.Arg616Lys	missense splice_region	Exon 21 of 38	NP_001005505.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CACNA2D2	ENST00000424201.7	TSL:1 MANE Select	c.1847G>A	p.Arg616Lys	missense splice_region	Exon 21 of 38	ENSP00000390329.2
	CACNA2D2	ENST00000423994.6	TSL:5	c.1847G>A	p.Arg616Lys	missense splice_region	Exon 21 of 39	ENSP00000407393.2
	CACNA2D2	ENST00000479441.1	TSL:1	c.1847G>A	p.Arg616Lys	missense splice_region	Exon 21 of 39	ENSP00000418081.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000363 AC: 53 AN: 1461084 Hom.: 0 Cov.: 35 AF XY: 0.0000385 AC XY: 28 AN XY: 726850

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52720

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.0000459 AC: 51 AN: 1111952

Other (OTH) AF: 0.0000166 AC: 1 AN: 60374

GnomAD4 genome Cov.: 33

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy Uncertain:1

Nov 23, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. ClinVar contains an entry for this variant (Variation ID: 530497). This variant has not been reported in the literature in individuals affected with CACNA2D2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 616 of the CACNA2D2 protein (p.Arg616Lys).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Uncertain	0.069	D
BayesDel_noAF	Benign	-0.14
CADD	Pathogenic	34
DANN	Uncertain	0.98
DEOGEN2	Benign	0.0073	T
Eigen	Benign	0.055
Eigen_PC	Benign	0.14
FATHMM_MKL	Uncertain	0.76	D
LIST_S2	Uncertain	0.95	D
M_CAP	Benign	0.038	D
MetaRNN	Benign	0.37	T
MetaSVM	Benign	-0.47	T
MutationAssessor	Benign	1.8	L
PhyloP100		4.7
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-0.88	N
REVEL	Uncertain	0.41
Sift	Benign	0.45	T
Sift4G	Uncertain	0.021	D
Polyphen		0.72	P
Vest4		0.49
MVP		0.51
MPC		0.85
ClinPred		0.74	D
GERP RS		4.7
Varity_R		0.14
gMVP		0.75
Mutation Taster		=60/40	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.44
dbscSNV1_RF	Benign	0.52
SpliceAI score (max)		0.80		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.80		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs371214569; hg19: chr3-50413135;