This group studied AD and PD families that showed linkage to chromosome 10, using the age-at-onset phenotype [13] and identified association of multiple SNPs at the GSTO locus with delayed age-at-onset of both diseases[5], with the strongest effects observed for GSTO1 rs4925 and GSTO2 rs2297235 SNPs that are in tight linkage disequilibrium (LD). This evidence concerns the gene GSTO1 and Parkinson disease.