2-47161626-C-T

Variant names:

• chr2-47161626-C-T
• rs2454084
• NM_001743.6:c.421+97G>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001743.6(CALM2):​c.421+97G>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 0.0000022 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CALM2 NM_001743.6 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.765
• Publications: 0 publications found

Genes affected

CALM2 (HGNC:1445): (calmodulin 2) This gene is a member of the calmodulin gene family. There are three distinct calmodulin genes dispersed throughout the genome that encode the identical protein, but differ at the nucleotide level. Calmodulin is a calcium binding protein that plays a role in signaling pathways, cell cycle progression and proliferation. Several infants with severe forms of long-QT syndrome (LQTS) who displayed life-threatening ventricular arrhythmias together with delayed neurodevelopment and epilepsy were found to have mutations in either this gene or another member of the calmodulin gene family (PMID:23388215). Mutations in this gene have also been identified in patients with less severe forms of LQTS (PMID:24917665), while mutations in another calmodulin gene family member have been associated with catecholaminergic polymorphic ventricular tachycardia (CPVT)(PMID:23040497), a rare disorder thought to be the cause of a significant fraction of sudden cardiac deaths in young individuals. Pseudogenes of this gene are found on chromosomes 10, 13, and 17. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Mar 2015]

CALM2 Gene-Disease associations (from GenCC):

• long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 15

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• catecholaminergic polymorphic ventricular tachycardia

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: G2P, Genomics England PanelApp, ClinGen

ENSG00000273269 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.96).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001743.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CALM2	NM_001743.6	MANE Select	c.421+97G>A		intron	N/A	NP_001734.1	P0DP24
	CALM2	NM_001305624.1		c.565+97G>A		intron	N/A	NP_001292553.1	P0DP24
	CALM2	NM_001305625.2		c.313+97G>A		intron	N/A	NP_001292554.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CALM2	ENST00000272298.12	TSL:1 MANE Select	c.421+97G>A		intron	N/A	ENSP00000272298.7	P0DP24
	ENSG00000273269	ENST00000422269.1	TSL:2	n.101-8610G>A		intron	N/A	ENSP00000476793.1	V9GYI7
	CALM2	ENST00000460218.5	TSL:1	n.3861+97G>A		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000220 AC: 2 AN: 909886 Hom.: 0 AF XY: 0.00000217 AC XY: 1 AN XY: 460514

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 13280

American (AMR) AF: 0.00 AC: 0 AN: 22130

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 17168

East Asian (EAS) AF: 0.00 AC: 0 AN: 34010

South Asian (SAS) AF: 0.00 AC: 0 AN: 52034

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 46866

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 2900

European-Non Finnish (NFE) AF: 0.00000147 AC: 1 AN: 681706

Other (OTH) AF: 0.0000251 AC: 1 AN: 39792

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 29

Alfa AF: 0.00 Hom.: 1308

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.96
CADD	Benign	0.023
DANN	Benign	0.75
PhyloP100		-0.77

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

Other links and lift over

dbSNP: rs2454084; hg19: chr2-47388765;