Usually, familial PD-linked loci are confined to a few families, but many unique families across the globe were linked to PARK8. 3–5 Not surprisingly, the discovery of mutations in the LRRK2 gene in late 2004 was disclosed by several genetic groups collaborating into two independent articles published at the same time.6,7 Many other groups around the world soon followed with additional disclosures of LRRK2 mutations.8–10. The gene discussed is LRRK2; the disease is Parkinson disease.