KCNJ2
Chr 17ADpotassium inwardly rectifying channel subfamily J member 2
Also known as: ATFB9, HHBIRK1, HHIRK1, IRK1, KIR2.1, LQT7, SQT3
The protein is an inward-rectifier potassium channel that allows potassium to flow preferentially into cells and participates in establishing action potential waveform and excitability of neuronal and muscle tissues. Mutations cause autosomal dominant Andersen syndrome characterized by periodic paralysis, cardiac arrhythmias, and dysmorphic features, as well as familial atrial fibrillation and short QT syndrome. The predicted mechanism is gain-of-function.
No known disease relationship
4 total gene-disease associations curated
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Moderately missense-constrained (top ~2.5%)
This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.
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
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
KCNJ2 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools