Key features:
(1) cardiac arrhythmias (ventricular arrhythmias, QT prolongation, torsade de pointes, bigeminy)
(2) dysmorphic features (low set ears, broad-base nose, short stature, hypertelorism, syndactyly, micrognathia, cleft or high-arched palate, scoliosis)
(3) periodic paralysis
Inheritance: autosomal dominant
Protein affected: potassium inwardly-rectifying channel (Kir)
Mutations often affect the residues implicated in in binding membrane-associated phosphatidylinositol 4,5-bisphosphate (PIP2).
Many families have mutations in KCNJ2 (KIR2.1) located on 17q24.3.
