CALM2

Chr 2AD

calmodulin 2

Also known as: CALM, CALML2, CAM1, CAM3, CAMC, CAMII, CAMIII, LQT15

Calmodulin mediates calcium signal transduction by binding calcium and regulating numerous enzymes, ion channels, and proteins throughout the cell. Mutations cause Long QT syndrome 15, which can present in infancy with life-threatening ventricular arrhythmias, delayed neurodevelopment, and epilepsy, inherited in an autosomal dominant pattern. The gene is highly constrained against loss-of-function variants, reflecting its essential cellular role.

Summary from RefSeq, OMIM, UniProt
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Primary Disease Associations & Inheritance

Long QT syndrome 15MIM #616249
AD
1
Active trials
22
Pubs (1 yr)
48
P/LP submissions
58%
P/LP missense
0.37
LOEUF
Multiple*
Mechanism· predicted
Clinical SummaryCALM2
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Gene-Disease Validity (ClinGen)
catecholaminergic polymorphic ventricular tachycardia · ADModerate

Moderate evidence — consider for supplementary testing

2 total gene-disease associations curated

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 0.92). One damaged copy is likely sufficient to cause disease.
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ClinVar Variants
33 unique Pathogenic / Likely Pathogenic· 77 VUS of 260 total submissions
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Clinical Trials
1 active or recruiting trial — potential therapeutic options may be available
📖
GeneReview available — CALM2
Authoritative clinical overview · Recommended first read
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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

LoF intolerant — likely haploinsufficient
LoF Constraint
0.37LOEUF
pLI 0.921
Z-score 2.64
OE 0.00 (0.000.37)
Highly constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
2.79Z-score
OE missense 0.10 (0.060.19)
8 obs / 76.9 exp
Mild constraint

Moderately missense-constrained (top ~2.5%)

Observed / Expected Ratios
LoF OE0.00 (0.000.37)
00.351.4
Missense OE0.10 (0.060.19)
00.61.4
Synonymous OE0.93
01.21.6
LoF obs/exp: 0 / 8.1Missense obs/exp: 8 / 76.9Syn Z: 0.26
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveCALM2-related long QT syndromeOTHERAD
moderateCALM2-related catecholaminergic polymorphic ventricular tachycardiaOTHERAD
DN
0.7131th %ile
GOF
0.4777th %ile
LOF
0.54top 25%

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and loss-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median · 1 literature citation
LOFLOEUF 0.37

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Literature Evidence

DNAllele-specific ablation rescues electrophysiological abnormalities in a human iPS cell model of long-QT syndrome with a CALM2 mutation.PMID:28335032

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

260 submitted variants in ClinVar

Classification Summary

Pathogenic22
Likely Pathogenic11
VUS77
Likely Benign123
Benign14
Conflicting5
22
Pathogenic
11
Likely Pathogenic
77
VUS
123
Likely Benign
14
Benign
5
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
10
12
0
22
Likely Pathogenic
0
9
2
0
11
VUS
2
48
22
5
77
Likely Benign
0
5
83
35
123
Benign
0
0
14
0
14
Conflicting
5
Total27213340252

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

CALM2 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Clinical Literature
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