There was no significant correlation between 24OHC levels and age in controls (r = 0.18, p = 0.45), PD (r = 0.01, p = 0.95) or CBD (r = 0.09, p = 0.83) subjects, whereas there was a positive correlation in CBS patients (r = 0.81, p = 0.003). This evidence concerns the gene CBS and Parkinson disease.