One patient with DLB (0.1% of n=980) (age of onset in 60s, and death early 70s) had a LRRK2 p.M1646T mutation associated with PD, and a TREM2 p.R62H mutation associated with AD.15 A patient with AD developing in the seventh decade of life had a PSEN2 p.L204I mutation and the TREM2 p.R62H risk factor. The gene discussed is PSEN2; the disease is Parkinson disease.