ASSOCIATION BETWEEN THE OXIDATIVE POLYMORPHISM AND EARLY-ONSET OF PARKINSONS-DISEASE

The frequency of five cytochrome P450IID6 allelic variants was studied in deoxyribonucleic acid from 123 patients with Parkinson's disease and 150 healthy volunteers, This was achieved by the use of mutation-specific polymerase chain reaction and restriction fragment length polymorphism, The analyses of the C gamma P2D6 genotype revealed no evidence for a higher prevalence of poor metabolizers among patients with Parkinson's disease. However, increased frequency of patients with Parkinson's disease with the genotype C gamma P2D6wt/C gamma P2D6B was observed, This is attributable exclusively to subjects with early onset of the disease (28 to 49 years), with a relative risk ratio of 4.16 (95% confidence limits, 2.0 to 8.3; p < 0.0005), The subjects who had late-onset Parkinson's disease (greater than or equal to 50 years) had genotypes and C gamma P2D6 allele frequencies similar to the healthy subjects, This indicates that the oxidative polymorphism is related to early-onset but not to late-onset Parkinson's disease. A different influence of C gamma P2D6 genotype on the risk of development of Parkinson's disease is observed in Spaniards, compared with previous findings in British subjects, These results suggest the combined effect of environmental toxins and C gamma P2D6 in the cause of Parkinson's disease.