Is CALM2 p.Ala103Val (c.308C>T) pathogenic?

CALM2 p.Ala103Val (c.308C>T) is classified Uncertain significance in CALM2 (ClinVar, Single submitter, 1 submitter; last evaluated 2023-08-14). Absent from gnomAD v4.1; Associated with long QT syndrome 1.

What condition is associated with CALM2 p.Ala103Val (c.308C>T)?

CALM2 p.Ala103Val (c.308C>T) is associated with long QT syndrome 1 (ClinVar).

How common is CALM2 p.Ala103Val (c.308C>T) in the general population?

CALM2 p.Ala103Val (c.308C>T) is absent from gnomAD v4.1 (gnomAD).

How is Romano-Ward syndrome inherited?

Typically Autosomal dominant, Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

CALM2 p.Ala103Val

c.308C>T · rs2465707262 · VCV2871265

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

long QT syndrome 1

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
REVEL	0.814	moderately pathogenic-leaning
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 12	GERP 2.2, phastCons 1
Regional constraint	o/e 0.21	constrained · MANE · 16 kb · p 6.7e-26 · regional, not allelic
Overall
CADD	31.0	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: CALM2
Protein: p.Ala103Val
Coding: c.308C>T
MANE Select: NM_001743
dbSNP: rs2465707262
Type: single nucleotide variant
Location: chr2:47161836 (GRCh38)
Gene constraint: LOEUF 0.262 · pLI 0.99 · ClinGen HI 0/3 (gnomAD)
Structure: AlphaFold pLDDT 85.82 · 21 PDB
Residue 103: the ef-hand 3 domain; the 'necessary and sufficient for interaction with pcp4' region; an α-helix

Full CALM2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

long QT syndrome 1 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Romano-Ward syndrome (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive
Onset: All ages
Prevalence: 1-5 / 10 000 (Europe)

Similar variants

CALM2 p.Ala103Thr Uncertain significance ★ same residue
CALM2 p.Asn98Ser Pathogenic ★★ same condition
CALM2 p.Asp134Asn Likely pathogenic ★★ same condition
CALM2 p.Asp96Tyr Pathogenic/Likely pathogenic ★★ same condition
CALM2 p.Asp96Val Pathogenic ★★ same condition
CALM2 c.285+5G>A Uncertain significance ★★ same condition
CALM2 p.Ala58Pro Uncertain significance ★★ same condition
CALM2 p.Arg107Cys Uncertain significance ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/calm2-p-ala103val (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown