On one hand, the variants detected in PSEN2, CHMP2B, SQSTM1 and PARK2 are exceptionally rare in the general population.22 Given the clinical, pathological and mechanistic overlap between DLB and the neurodegenerative disorders where these disease genes were first described, it is plausible that they are contributing to the neuropathology. The gene discussed is PSEN2; the disease is Lewy body dementia.