Several lines of evidence support the presence of DNA damage in somatic cel
ls of Parkinson's disease (PD) patients due to the formation of free radica
l species. In order to detect spontaneous chromosome and primary or oxidati
ve DNA damage, we performed the human lymphocyte micronucleus assay (HLMNA)
and comet assay in 19 PD patients and 16 healthy controls. Compared with c
ontrols, PD patients showed a significant increase in: (1) spontaneous micr
onucleus (MN) frequency (p<0.001); (2) single strand break (SSB) levels (p<
0.001); and (3) oxidized purine base levels (p<0.05). The chromosome damage
and the increased levels of oxidized purine bases observed in our patients
support the hypothesis of oxidative stress as a relevant factor in the pat
hogenesis of PD.