However, they may also include neuroplasticity consequences of COMT, APOE and MAPT functional polymorphisms in the context of Parkinson’s disease pathogenesis, or developmental effects even if these diminish with older age (e.g. for COMT) (de Frias et al., 2005; Starr et al., 2007; Rowe et al., 2010). This evidence concerns the gene COMT and Parkinson disease.