Andersen Tawil syndrome: genes and variants
Andersen Tawil syndrome is linked to 1 analyzed protein (KCNJ2). 34 DNA variants are known to cause it; 191 more are uncertain, and 8 of those already look disease-causing on computable evidence.
Last updated 2026-09-30. Research information, not medical advice.
Also known as: Andersen-Tawil syndrome
Genes linked to Andersen Tawil syndrome
KCNJ2: Inward rectifier potassium channel 2
Its inward-rectifier current stabilizes the resting membrane potential in cardiac and skeletal muscle and contributes to terminal cardiac repolarization. Loss-of-function variants cause Andersen-Tawil syndrome, while gain-of-function variants can cause short-QT syndrome.
34 disease-causing and 191 uncertain variants in KCNJ2 are linked to Andersen Tawil syndrome.
Where Andersen Tawil syndrome variants cluster
- KCNJ2 Selectivity filter (positions 142–147): 5 of 34 disease-causing changes, 10.5× more than its size predicts.
- KCNJ2 Polyphosphoinositide (PIP2)-binding (positions 181–208): 4 of 34 disease-causing changes, 1.8× more than its size predicts.
- KCNJ2 Transmembrane (positions 82–106): 3 of 34 disease-causing changes, 1.5× more than its size predicts.
Known disease-causing variants in Andersen Tawil syndrome
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| KCNJ2 R82Q | 82 | Transmembrane | Disease-causing (★★) |
| KCNJ2 R82W | 82 | Transmembrane | Disease-causing (★★) |
| KCNJ2 G144S | 144 | Pore-forming | Disease-causing (★★) |
| KCNJ2 R312H | 312 | Cytoplasmic | Disease-causing (★★) |
| KCNJ2 R312C | 312 | Cytoplasmic | Disease-causing (★★) |
| KCNJ2 G144A | 144 | Pore-forming | Disease-causing (★★) |
| KCNJ2 G144D | 144 | Pore-forming | Disease-causing (★★) |
| KCNJ2 R218W | 218 | Cytoplasmic | Disease-causing (★★) |
| KCNJ2 R218P | 218 | Cytoplasmic | Disease-causing (★★) |
| KCNJ2 R218Q | 218 | Cytoplasmic | Disease-causing (★★) |
| KCNJ2 G146S | 146 | Pore-forming | Disease-causing (★★) |
| KCNJ2 R189G | 189 | Polyphosphoinositide (PIP2)-binding | Disease-causing (★★) |
| KCNJ2 G300V | 300 | Cytoplasmic | Disease-causing (★★) |
| KCNJ2 R67Q | 67 | Cytoplasmic | Disease-causing (★★) |
| KCNJ2 T75K | 75 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 T75R | 75 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 D78N | 78 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 D78Y | 78 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 P186Q | 186 | Polyphosphoinositide (PIP2)-binding | Disease-causing (★) |
| KCNJ2 T305A | 305 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 T309I | 309 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 Y145C | 145 | Pore-forming | Disease-causing (★) |
| KCNJ2 G215D | 215 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 N216Y | 216 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 E299G | 299 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 R260H | 260 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 C54F | 54 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 D71V | 71 | Cytoplasmic | Disease-causing (★) |
| KCNJ2 D172N | 172 | Transmembrane | Disease-causing (★) |
| KCNJ2 T192A | 192 | Polyphosphoinositide (PIP2)-binding | Disease-causing (★) |
| KCNJ2 L90R | 90 | Transmembrane | Disease-causing (★) |
| KCNJ2 P186L | 186 | Polyphosphoinositide (PIP2)-binding | Disease-causing |
| KCNJ2 T305P | 305 | Cytoplasmic | Disease-causing |
| KCNJ2 V302M | 302 | Cytoplasmic | Disease-causing |
Uncertain variants in Andersen Tawil syndrome that look disease-causing
| Variant | Position | Protein part | Clinical label | Evidence |
|---|---|---|---|---|
| KCNJ2 G144V | 144 | Pore-forming | Conflicting reports (★) | +6: 5 other pathogenic changes within 3 positions; G144A at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 1.00 |
| KCNJ2 T192I | 192 | Polyphosphoinositide (PIP2)-binding | Conflicting reports (★) | +6: 2 other pathogenic changes within 3 positions; T192A at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 1.00 |
| KCNJ2 R218L | 218 | Cytoplasmic | Conflicting reports (★) | +6: 5 other pathogenic changes within 3 positions; R218W at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 1.00 |
| KCNJ2 R189K | 189 | Polyphosphoinositide (PIP2)-binding | Conflicting reports (★) | +6: 4 other pathogenic changes within 3 positions; R189G at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 0.98 |
| KCNJ2 G146D | 146 | Pore-forming | Uncertain (★) | +6: 5 other pathogenic changes within 3 positions; G146S at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 1.00 |
| KCNJ2 D78H | 78 | Cytoplasmic | Uncertain (★) | +6: 4 other pathogenic changes within 3 positions; D78N at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 0.99 |
| KCNJ2 N216I | 216 | Cytoplasmic | Uncertain (★) | +6: 5 other pathogenic changes within 3 positions; N216Y at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 0.99 |
| KCNJ2 R189T | 189 | Polyphosphoinositide (PIP2)-binding | Uncertain (★) | +6: 4 other pathogenic changes within 3 positions; R189G at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 0.98 |
Diseases related to Andersen Tawil syndrome
- Long QT syndrome, also linked to KCNJ2
- Cardiac arrhythmia, also linked to KCNJ2
- Short QT syndrome type 3, also linked to KCNJ2
- Atrial fibrillation, familial, 10, also linked to KCNJ2
Frequently asked questions
Which genes are linked to Andersen Tawil syndrome?
In CATVariant, Andersen Tawil syndrome is linked to 1 analyzed protein: KCNJ2 (Inward rectifier potassium channel 2).
How many genetic variants are linked to Andersen Tawil syndrome?
240 variants: 34 are classified as disease-causing (pathogenic or likely pathogenic) in ClinVar and 191 are of uncertain significance or have conflicting reports.
Which uncertain variants in Andersen Tawil syndrome look disease-causing?
8 uncertain variants reach the likely-pathogenic range of the ACMG/AMP points scale on computable evidence, for example KCNJ2 G144V, KCNJ2 T192I, KCNJ2 R218L, KCNJ2 R189K and KCNJ2 G146D. These are leads for expert review, not diagnoses.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from the latest public CATVariant analysis of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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