To validate the role of the RAB39B gene in susceptibility to familial PD in the Chinese Han population, we conducted this study in 195 families consisting of PD patients with AD and AR inheritance, in whom the common causative genetic mutations, in genes such as SNCA, LRRK2, UCHL1, HtrA2, GIGYF2, EIGIF4, parkin, PINK1, DJ-1, ATP13A2, and PLA2G6, had previously been excluded7, 8, 9. The gene discussed is SNCA; the disease is Parkinson disease.