In another familial form of PD (PARK9 or Kufor-Rakeb syndrome, #606693), caused by mutations in ATP13A2 (PARK9) encoding a lysosomal P-type ATPase,76 patients displayed typical eye movement abnormalities, including slow saccades with worse precision and increased latency of horizontal saccades.77 The gene discussed is ATP13A2; the disease is parkinsonism due to ATP13A2 deficiency.