PINK1 and Parkinson disease: PD is thought to be caused by a combination of genetic and environmental factors, with only around 10% of people with PD having one of the identified genetic mutations, such as SNCA (Synuclein Alpha), PINK1 (PTEN Induced Kinase 1), and PRKN (Parkin RBR E3 ubiquitin protein ligase) (4).