Meta‐analysis showed both no association between COMT Val108/158Met SNP and PD regardless of ethnicity (Jiménez‐Jiménez, Alonso‐Navarro, García‐Martín, & Agúndez, 2014) and association of COMT Val158Met PSN and the risk of PD in Asians rather than Caucasians (Lechun, Yu, Pengling, & Canggi, 2013). This evidence concerns the gene COMT and Parkinson disease.