(allele A vs G: OR = 1.33, 95%CI = 1.11-1.58; AA vs GG: OR = 1.46, 95%CI = 1.09-1.97; AA + AG vs GG: OR = 1.42, 95%CI = 1.06-1.90). Similarly, population-based studies also showed significant association between the MAOB A644G polymorphism and PD risk among different populations