1-115700034-T-C

Variant names:

• chr1-115700034-T-C
• rs183297938
• NM_001232.4:c.*1207A>G

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 0P and 7B. BP4_Moderate BS1_Supporting BS2

The NM_001232.4(CASQ2):​c.*1207A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0029 in 152,636 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0028 (7 hom., cov: 33)
  • Exomes 𝑓: 0.026 (0 hom.)
• Consequence: CASQ2 NM_001232.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0710

Genes affected

CASQ2 (HGNC:1513): (calsequestrin 2) The protein encoded by this gene specifies the cardiac muscle family member of the calsequestrin family. Calsequestrin is localized to the sarcoplasmic reticulum in cardiac and slow skeletal muscle cells. The protein is a calcium binding protein that stores calcium for muscle function. Mutations in this gene cause stress-induced polymorphic ventricular tachycardia, also referred to as catecholaminergic polymorphic ventricular tachycardia 2 (CPVT2), a disease characterized by bidirectional ventricular tachycardia that may lead to cardiac arrest. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Benign. Variant got -7 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.26).
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00285 (434/152326) while in subpopulation NFE AF= 0.00072 (49/68030). AF 95% confidence interval is 0.00056. There are 7 homozygotes in gnomad4. There are 323 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAd4 at 7 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CASQ2	NM_001232.4	c.*1207A>G		3_prime_UTR_variant	Exon 11 of 11	ENST00000261448.6	NP_001223.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CASQ2	ENST00000261448	c.*1207A>G		3_prime_UTR_variant	Exon 11 of 11	1	NM_001232.4	ENSP00000261448.5
CASQ2	ENST00000488931.2	n.*1779A>G		non_coding_transcript_exon_variant	Exon 13 of 13	3		ENSP00000518226.1
CASQ2	ENST00000488931.2	n.*1779A>G		3_prime_UTR_variant	Exon 13 of 13	3		ENSP00000518226.1

Frequencies

GnomAD3 genomes AF: 0.00285 AC: 434 AN: 152208 Hom.: 7 Cov.: 33

Gnomad AFR AF: 0.0000724

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: 0.0356

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000720

Gnomad OTH AF: 0.00191

GnomAD4 exome AF: 0.0258 AC: 8 AN: 310 Hom.: 0 Cov.: 0 AF XY: 0.0208 AC XY: 4 AN XY: 192

Gnomad4 FIN exome AF: 0.0230

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.250

GnomAD4 genome AF: 0.00285 AC: 434 AN: 152326 Hom.: 7 Cov.: 33 AF XY: 0.00434 AC XY: 323 AN XY: 74482

Gnomad4 AFR AF: 0.0000722

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.0356

Gnomad4 NFE AF: 0.000720

Gnomad4 OTH AF: 0.00189

Alfa AF: 0.00154 Hom.: 0

Bravo AF: 0.000196

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Catecholaminergic polymorphic ventricular tachycardia 2 Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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	-0.26
CADD	Benign	7.7
DANN	Benign	0.84

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: rs183297938; hg19: chr1-116242655;