LRRK2 and Parkinson disease: Mutation in the LRRK2 gene, encoding for leucine-rich repeat kinase 2 protein, first mapped in 200213, is much more commonly implicated than SNCA, accounting for 4% of familial and 1% of sporadic cases of PD, but in certain populations may account for up to 10% of all “sporadic” PD and 42% of familial cases in Europe and North Africa, particularly in North African Berbers, Iberian populations, and Ashkenazi Jews (13% sporadic and 30% familial)14,15.