We further investigated the association of CGG repeat size and the age at onset of PD, but no correlation was found between the CGG repeat size of the FMR1 gene and age at onset, neither in normal repeat size (linear regression and Pearson’s correlation, r = 0.017, P-value = 0.957) nor in GZ allele (r = 0.025, P-value = 0.235) of FMR1 gene CGG repeat (Figure 4). This evidence concerns the gene FMR1 and Parkinson disease.