GBA1 and Parkinson disease: 2010). Cumulative genetic risk reduces the age‐of‐onset of PD. Meta‐analyses of genome‐wide association studies have identified 28 risk loci associated with PD (Nalls et al. 2015). Of these, the most statistically significant signals associated are common substitutions located close to the SNCA (OMIM: 163890), LRRK2 (OMIM: 609007), MAPT (OMIM: 157140) genes and low‐frequency coding substitutions in the GBA (OMIM: 606463) gene (Benitez et al. 2016).