2-151833977-G-A

Position:

• chr2-151833977-G-A

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP4_Strong BS2

The NM_000726.5(CACNB4):​c.*5142C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000191 in 152,114 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.00019 (2 hom., cov: 32)
• Consequence: CACNB4 NM_000726.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.34

Genes affected

CACNB4 (HGNC:1404): (calcium voltage-gated channel auxiliary subunit beta 4) This gene encodes a member of the beta subunit family of voltage-dependent calcium channel complex proteins. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization and consist of a complex of alpha-1, alpha-2/delta, beta, and gamma subunits in a 1:1:1:1 ratio. Various versions of each of these subunits exist, either expressed from similar genes or the result of alternative splicing. The protein encoded by this locus plays an important role in calcium channel function by modulating G protein inhibition, increasing peak calcium current, controlling the alpha-1 subunit membrane targeting and shifting the voltage dependence of activation and inactivation. Certain mutations in this gene have been associated with idiopathic generalized epilepsy (IGE), juvenile myoclonic epilepsy (JME), and episodic ataxia, type 5. [provided by RefSeq, Aug 2016]

ACMG classification

Verdict is Benign. Variant got -8 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.49).
• BS2: High AC in GnomAd4 at 29 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CACNB4	NM_000726.5	c.*5142C>T		3_prime_UTR_variant	14/14	ENST00000539935.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CACNB4	ENST00000539935.7	c.*5142C>T		3_prime_UTR_variant	14/14	1	NM_000726.5

Frequencies

GnomAD3 genomes AF: 0.000151 AC: 23 AN: 151996 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000314

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000197

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.00103

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 0

GnomAD4 genome AF: 0.000191 AC: 29 AN: 152114 Hom.: 2 Cov.: 32 AF XY: 0.000269 AC XY: 20 AN XY: 74364

Gnomad4 AFR AF: 0.000457

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00104

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.000159

Asia WGS AF: 0.00144 AC: 5 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Episodic ataxia type 5 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.49
CADD	Benign	14
DANN	Benign	0.87

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs112953474; hg19: chr2-152690491;