Correlations of CYP11B2 gene polymorphisms with eclampsia

The aim of this study was to explore the relationship between CYP11B2 gene polymorphisms and eclampsia.

A total of 400 pregnant women treated in our hospital were enrolled in this study, including 200 normal pregnant women (pregnancy group) and 200 pregnant women with eclampsia (eclampsia group). Peripheral blood was collected from subjects of the two groups. Subsequently, genomic deoxyribonucleic acids (DNAs) were extracted and amplified via polymerase chain reaction (PCR) for detection of CYP11B2 rs4543, rs3802228 and rs104894072 polymorphisms. The expression level of CYP11B2 gene was measured as well. Additionally, the correlations of CYP11B2 gene polymorphisms with blood pressure and coagulation and renal function indexes were analyzed.

The distribution of alleles of rs4543 locus in CYP11B2 gene was significantly different between eclampsia group and pregnancy group (p=0.027). The frequency of the allele C was significantly lower in eclampsia group than that of pregnancy group (p<0.05). There was a statistically significant difference in the genotype distribution of CYP11B2 rs3802228 (p=0.000) and rs104894072 (p=0.000) between eclampsia group and pregnancy group (p<0.05). Meanwhile, the frequency of AA genotype of rs3802228 and TG genotype of rs104894072 was remarkably higher in eclampsia group than that in pregnancy group (p<0.05). The distribution of the locus rs104894072 (p=0.044) in dominant model and rs3802228 (p=0.002) in recessive model in eclampsia group was different from that in pregnancy group (p<0.05). Eclampsia group showed remarkably elevated frequency of TT + TG of the locus rs104894072 in dominant model and lowered frequency of AG + GG of the locus rs3802228 in recessive model (p<0.05). Similarly, a significant difference was observed in the distribution of the haplotypes CGG (p=0.001) and TGT (p=0.048) in CYP11B2 gene between eclampsia group and pregnancy group (p<0.05). The linkage disequilibrium of the loci rs3802228 and rs104894072 was relatively high (D'=0.382). The polymorphism of the locus rs104894072 in CYP11B2 gene had an evident relation to CYP11B2 gene expression (p<0.05). Meanwhile, the expression of CYP11B2 gene was markedly higher in patients with GG genotype in eclampsia group (p<0.05). The polymorphism of CYP11B2 rs4543 was notably associated with PT level of patients in eclampsia group (p=0.000). Conversely, rs3802228 polymorphism was correlated with 24 h urine protein level (p=0.000). Besides, the proportion of patients with CGG haplotype was significantly larger among patients with systolic blood pressure of 140-160 mmHg (p<0.05). In addition, the proportion of patients with TGT haplotype was evidently greater among patients with systolic blood pressure >180 mmHg in eclampsia group (p<0.05).

CYP11B2 gene polymorphisms are significantly correlated with the development and progression of eclampsia.