1-115725505-T-C

Position:

• chr1-115725505-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001232.4(CASQ2):​c.783+3A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000157 in 1,460,592 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: not found (cov: 31)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: CASQ2 NM_001232.4 splice_region, intron
• Scores: Splicing: ADA: 0.9920
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.23

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CASQ2	NM_001232.4	c.783+3A>G		splice_region_variant, intron_variant		ENST00000261448.6	NP_001223.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CASQ2	ENST00000261448.6	c.783+3A>G		splice_region_variant, intron_variant		1	NM_001232.4	ENSP00000261448.5
CASQ2	ENST00000488931.2	n.*155+3A>G		splice_region_variant, intron_variant		3		ENSP00000518226.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.0000157 AC: 23 AN: 1460592 Hom.: 0 Cov.: 34 AF XY: 0.0000179 AC XY: 13 AN XY: 726626

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: 0.0000198

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 31

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Catecholaminergic polymorphic ventricular tachycardia 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 30, 2018

This sequence change falls in intron 7 of the CASQ2 gene. It does not directly change the encoded amino acid sequence of the CASQ2 protein, but it affects a nucleotide within the consensus splice site of the intron. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with CASQ2-related disease. Nucleotide substitutions within 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 disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. 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	-0.25
CADD	Benign	22
DANN	Benign	0.96

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Benign	0.72
SpliceAI score (max)		0.31		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.31		Position offset: 3

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

Publications

LitVar

Other links and lift over

dbSNP: rs876657751; hg19: chr1-116268126;