rs775272200

chr3-50380742-G-Achr3-50380742-G-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_006030.4(CACNA2D2):c.842+6C>T variant causes a splice donor region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000157 in 1,525,956 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 (★★).

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: CACNA2D2 NM_006030.4 splice_donor_region, intron
• Scores: Splicing: ADA: 0.00002994
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.290

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 Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.0000526 (8/152138) while in subpopulation AMR AF= 0.000327 (5/15286). AF 95% confidence interval is 0.000129. There are 0 homozygotes in gnomad4. There are 5 alleles in male gnomad4 subpopulation. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNA2D2	NM_006030.4	c.842+6C>T		splice_donor_region_variant, intron_variant		ENST00000424201.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNA2D2	ENST00000424201.7	c.842+6C>T		splice_donor_region_variant, intron_variant		1	NM_006030.4	P4

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152138 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000327

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

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

GnomAD3 exomes AF: 0.0000356 AC: 6 AN: 168590 Hom.: 0 AF XY: 0.0000222 AC XY: 2 AN XY: 89996

Gnomad AFR exome AF: 0.0000810

Gnomad AMR exome AF: 0.000137

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000736

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000607

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000116 AC: 16 AN: 1373818 Hom.: 0 Cov.: 31 AF XY: 0.00000741 AC XY: 5 AN XY: 674806

Gnomad4 AFR exome AF: 0.0000988

Gnomad4 AMR exome AF: 0.000160

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000269

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000468

Gnomad4 OTH exome AF: 0.0000354

GnomAD4 genome AF: 0.0000526 AC: 8 AN: 152138 Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5 AN XY: 74314

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.000327

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000477 Hom.: 0

Bravo AF: 0.0000453

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 05, 2022

The c.842+6C>T intronic alteration consists of a C to T substitution nucleotides after coding exon 8 in the CACNA2D2 gene. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Early infantile epileptic encephalopathy with suppression bursts Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 16, 2022

This sequence change falls in intron 8 of the CACNA2D2 gene. It does not directly change the encoded amino acid sequence of the CACNA2D2 protein. It affects a nucleotide within the consensus splice site. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with CACNA2D2-related conditions. ClinVar contains an entry for this variant (Variation ID: 530441). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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
BayesDel_noAF	Benign	-0.87
Cadd	Benign	6.1
Dann	Benign	0.49

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000030
dbscSNV1_RF	Benign	0.076
SpliceAI score (max)		0.020		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: rs775272200; hg19: chr3-50418173;