NPC1 and Tetraparesis: In a male patient (GM214) with neurodevelopmental delay, seizures, hepatosplenomegaly and tetraparesis, we detected two heterozygous P/LP variants in NPC1. The biomarker PPCS (C24H50O7N2P—legacy name lyso SM-509) was pathologically increased, which supported the diagnosis of Nieman-Pick disease type C1 in the patient.