SNCA and Parkinson disease: Compared with PINK1, PRKN, DJ-1, and SNCA, PD pathogenic mutations in LRRK2 are more common, with the most common LRRK2 mutation, Gly2019Ser (G2019S), accounting for 4% of familial and 1% of sporadic PD cases, and up to 36% of familial and 39% of iPD cases depending on ethnic background [10,48].