LRRK2 and Parkinson disease: For example, the most frequent LRRK2 mutation (G2019S) is found in 4% of familial and up to 1–2% of sporadic PD patients worldwide [3,6] and with much higher frequency, for example, in Ashkenazi Jews (28% of familial and 10% of sporadic PD) and North African Berbers (40% of familial and 30% of sporadic cases) [4,5,7].