DRD1 and DRD4 dopamine receptors in the etiology of preeclampsia

Recent reports have suggested an association between genetic polymorphisms of dopamine receptors and the development of an increased risk of chronic hypertension, as well as preeclampsia (PE). The aim of the study was to evaluate the impact of the -48A>G DRD1 and -521C>T DRD4 polymorphisms in the etiology of PE among Polish women. Ninety-eight preeclamptic women and 120 healthy pregnant controls were enrolled in the study The investigated polymorphisms of the DRD 1 and DRD4 genes were identified using PCR/RFLP methods. As far as the -48A>G DRD 1 polymorphism is concerned, the mutated -48GG genotype was more often found in controls (14.2%) than in the PE group (10.2%, ns), and the subgroup with severe PE (8.2%). Also, the frequency of the mutated -48G allele was higher in controls (39.6%) than in the PE group (33.2%, ns), and in the subgroup with severe PE (31.6%, ns). As for the -521C>TDRD4 polymorphism, a similar occurrence of the mutated -521 TTgenotype and the -521T allele in all of the investigate groups was observed. Lower serum concentrations of total protein (5.59 g/L and 5.57 g/L vs. 6.17 g/L in carriers of the -52100 genotype, p=0.02) were noted in patients with the mutated homozygous -521 TT genotype and heterozygous -521CT genotype of DRD4. The obtained results suggest a possible protective role of the mutated -48G DRD1 allele in the etiology of preeclampsia, especially its severe form. The presence of the mutated -521 T DRD4 allele could influence the decrease of total blood protein in preeclamptic patients. The observed frequency of dopamine DRD1 and DRD4 polymorphisms is similar to the distribution of these variants in other Caucasian populations.