A novel DYNC1H1 mutation causing spinal muscular atrophy with lower extremity predominance.

Recent studies have identified mutations in the dynein heavy chain gene (DYNC1H1), which lead to 2 closely related human motor neuropathies: a dominant spinal muscular atrophy with lower extremity predominance (SMALED) and axonal Charcot-Marie-Tooth (CMT) disease.(1,2) We describe the identification of a novel mutation (p.G807S) in DYNC1H1 as the cause of SMALED.