Using quantitative 18F-fluorodopa PET imaging, we have recently shown that the monoamine oxidase B gene intron 13 polymorphism (MAOB; rs1799836) predicts dopamine turnover in de novo PD with the MAOBCC/(C)/CT genotypes leading to lower dopamine turnover [15], which in turn has been associated with a decreased risk for motor complications [16]. Here, MAOB is linked to Parkinson disease.