GAK and Parkinson disease: Analysis of 24 PD associated-genes revealed compound effects between rare protein-altering variants and T1R in the interacting genes PRKN/PINK1 (P = 2.7–05; OR = 4.0) and a combination of rare/low frequency variants in the LRRK2/GAK pair (P = 6.7–05; OR = 0.54).