PD-causing genes, such as ATP13A2 (Ramirez et al., 2006), PLA2G6 (Paisan-Ruiz et al., 2009), FBXO7 (Di Fonzo et al., 2009), PRKN (Lucking et al., 2000; Djarmati et al., 2004), PINK1 (Bonifati et al., 2005; Kumazawa et al., 2008), and PARK7 (Djarmati et al., 2004) have been suggested be strongly associated with AAO. This evidence concerns the gene PLA2G6 and Parkinson disease.