Dopamine receptor D2 intronic polymorphism in patients with Parkinson's disease

An association between the intronic allele 3 of the dopamine receptor D2 (DRD2) gene and European Parkinson's disease (PD) cases has been reported recently. We initiated the present work in order to determine whether this association between the DRD2 locus and PD is also present in our population from Spain. The DRD2 gene polymorphism has been genotyped in 154 patients and in 125 controls. The allele 3 is present in 60.3% of the patients and in 55.2% of the controls. The genotype 3/3 is present in 36.3% of the patients and in 34.4% of the controls. No statistical differences in the genotype and allelic frequencies between the two groups have been found. No differences were also found when the patients were classified according to different criteria such as onset, family history, gender or clinical presentation. Thus our results do not support a role for the DRD2 locus to develop PD.