Notably, GDI1 has been associated with Intellectual developmental disorder, X-linked 41 (OMIM # 300,849), and RAB39B has been linked to Intellectual developmental disorder, X-linked 72 (OMIM # 300,271) and Waisman syndrome (OMIM # 311,510). Here, RAB39B is linked to Early-onset parkinsonism - intellectual disability.