LRRK1 is related to the familial Parkinsonism gene product Park8 (also known as LRRK2) and belongs to the ROCO family of proteins, which contain a Ras of complex proteins (ROC) GTPase domain and a MAPKKK-like kinase domain (Bosgraaf and Van Haastert, 2003). The gene discussed is LRRK1; the disease is Parkinson disease.