Maternal effect on Parkinson's disease

First-degree relatives of patients with Parkinson's disease (PD) are at hig her risk for PD development than first-degree relatives of control subjects , but clinical twin studies have failed to demonstrate a genetic basis in P D. It is hypothesized that maternal exposure to certain environmental facto rs could lead to pathological changes in the ovum that predispose to the de velopment of PD in the child. In this study of 299 patients and 295 control s, the age at onset of PD was found to correlate negatively with maternal a ge at birth of patient but not with paternal age. Mothers and fathers of pa tients with PD had an increased risk of PD as compared with parents of cont rol subjects. These results suggest a maternal effect on PD that could be p rimarily environmental in nature.