Association between a polymorphism of ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) gene and sporadic Parkinson's disease.

We found a novel polymorphism (S/Y18) of ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) gene a mutation of which is expected to contribute to the etiology of a form of familial Parkinson's disease (PD). We report the frequency of this polymorphism in 313 patients with sporadic PD and 302 control subjects (Japanese and Caucasians). The frequency of the mutant allele (Y) was significantly higher in Japanese control subjects (51.2%) than in Japanese PD patients (43.4%) (chi(2)=3.917, p=0.048<0.05). It appears that this polymorphism has a weak protective factor against PD in at least the Japanese population. The frequencies of Y allele and S/Y and Y/Y genotypes in the PD patients and the controls were more significantly higher in Japanese than in Caucasian population (p<0.0001). It seems that the role of this polymorphism in PD may be different between Caucasian and Japanese populations.