ABSTRACT
<p><b>OBJECTIVE</b>To investigate the frequencies of three polymorphisms in DJ-1 (g.168-185del; SNP405, refSNP ID:rs3766606 and 293 G/A) and their association with sporadic Parkinson's disease.</p><p><b>METHODS</b>An association study was performed to determine the genotype of each subject using polymerase chain reaction, restriction fragment length polymorphism and sequence analysis in 192 patients with sporadic Parkinson's disease and 198 healthy controls.</p><p><b>RESULTS</b>In the g.168-185del locus, the Ins/Ins genotype was common and the frequency of Del allele was very low (0.38%). The SNP of 293G/A was not detected in both groups. In the SNP405 G/T site, the GT genotype frequency was significantly higher in patients with age of onset before 40 years than in controls (18.75% vs 5.54%, P=0.004, OR=6.30 95%CI:1.96-20.18).</p><p><b>CONCLUSION</b>The results suggest that the frequencies of the g.168-185del and 293G/A polymorphisms might be different between Chinese and European. The SNP405 GT genotype might be a risk factor for sporadic Parkinson's disease with early age of onset in Sichuan Han population.</p>