Both genes are involved in the biotransformation process, and the main objective of that work is to assess synergic effect between CYP2D6 PM and GSTM1 null genotypes in PD patients.
However, a significantly elevated median age for the onset of PD was found among GSTM1 gene carriers (median age = 68 years) compared to PD patients being GSTM1 null genotypes (median age = 57 years).