Accordingly, it would be through these multiple short- and long-term interactions between parental genes and gestational environments that APOE polymorphism could influence neurodevelopmental trajectories during early life periods and infancy and later, by pre-establishing a higher risk for “aging-related” conditions, or at least influencing, clinical onset or phenotype in neurodegenerative diseases such as AD, Parkinson’s disease (PD) [140] or ALS [141]. The gene discussed is APOE; the disease is Parkinson disease.