VPS13A and Cohen syndrome: Although mutations in all four VPS13A-D genes are linked to developmental or neurodegenerative diseases, such as chorea acanthocytosis (ChAc; VPS13A), Cohen syndrome (VPS13B), early onset Parkinson’s disease (VPS13C), and ataxia-paraplegia (VPS13D) [1,2,3,4], the functions of the proteins they encode have only recently begun to be uncovered.