Exome sequencing of 91 cases of pathologically confirmed DLB identified four patients harbouring previously described pathogenic mutations neurodegenerative disease genes based on current diagnostic criteria (PSEN2, CHMP2B, SQSTM1, PARK2); possible pathogenic mutations in two (EIF4G1 and SQSTM1); and two further cases with mutations in GIGYF2, which has previously been associated with autosomal dominant PD. Here, PSEN2 is linked to Lewy body dementia.