PLA2G6 and Parkinson disease: AR mutations in the phospholipase A2 group (PLA2G6) are causative of the PLAN phenotypic spectrum (Table 1), including classic infantile neuronal dystrophy (INAD), atypical neuronal dystrophy (NAD) with childhood-onset, and an adult onset dystonia-parkinsonism form named PARK14 [85,86].