MAOB and Parkinson disease: For example, male PwP carriers of MAO-B G allele had a 2.84-fold increased risk of being treated with higher doses of levodopa (79); rs1113666 polymorphism of GAPDH gene was found to be a significant risk factor for PD, especially in male PwP (81); and A allele of rs7311174 and T allele of rs2072374 was reported to be protective in males (82).