In a larger study, 27 dual mutation patients (all with LRRK2 G2019S and a majority with mild GBA mutations) have significantly better motor function, lower rates of dementia and slower cognitive decline than both mild and severe GBA mutation carriers, again implying a modifying role of LRRK2 on motor and nonmotor phenotypes of patients with GBA mutations [94]. The gene discussed is GBA1; the disease is Mental deterioration.