<unk>  is very rare, and as of 2013 approximately 200 cases had been described in the medical literature. The condition is estimated to affect one person in every 1,000,000.
Andersen–Tawil syndrome
Jervell and Lange-Nielsen syndrome
Dennie–Marfan syndrome
Romano–Ward syndrome
Timothy syndrome
Marfan syndrome
Catecholaminergic polymorphic ventricular tachycardia
CAMFAK syndrome