CHRNA4 and sleep-related hypermotor epilepsy: Overall, 17 CHRNA4 mutations have been identified in patients with SHE to date, comprising missense mutations (S248F, I275F, S280F, S284L, S284W, T293I, R336H, G307V I265I, R308H, R483W, S252L, I248F, G570R, R360Q), an insertion mutation (L291dup), and a synonymous mutation (D190D) (3–6).