Association of APOE with Parkinson disease age-at-onset in women.

APOE polymorphism has received extensive attention as a risk factor for Parkinson's disease (PD), but findings have been equivocal. Analysis of APOE variants in an Australian PD case-control sample revealed a robust association between genotype and age-at-onset (AAO) of PD in women (P=0.0008). These data not only further implicate APOE in PD, but also provide a stark example of the effects that gender may play in complex disorders.