SLC5A7 and amyotrophic lateral sclerosis: Transporter assays revealed significant reductions in HC-3-sensitive choline uptake due to the p.Lys499Asnfs*13 mutation, consistent with a dominant-negative mode of action.1 Here, we report additional dominant truncating CHT mutations in 2 unrelated families for which individuals were referred initially with diagnoses of amyotrophic lateral sclerosis (ALS) based on a progressive pure motor neurogenic disorder with hyperreflexia, and Charcot-Marie-Tooth (CMT) type II based on distinct and progressive atrophy of the hand muscles and gait difficulties.