APOE and Parkinson disease: Specifically, single nucleotide polymorphisms in the gene encoding mitochondrial transcription factor A were found to be associated with PDD and not DLB.11 Also, the apolipoprotein e E4 allele frequency was higher in pure DLB (ie, without concomitant AD pathology) than in PDD.12 Furthermore, although GBA mutations are reported in both DLB and PD, pure DLB has an intermediate mutation frequency between AD and PD.13 A recent genomewide study of DLB also demonstrated different genetic risk factors when compared with PD.14