Effects of Klotho polymorphisms on Preeclampsia risk in a case-control study

Preeclampsia (PE) is a serious disorder of human pregnancy and always is accompanied with multi-organ disorder, which severely threatens the health of both the mothers and the offspring. The oxidative stress and genetic factors involves in the development of PE. The Klotho encodes Klotho protein that is capable of increasing resistance to oxidative stress. Thus, we designed this case-control study to investigate the association between Klotho polymorphisms and the susceptibility to PE in Chinese Han women. Two single nucleotide polymorphisms (SNPs) (rs1207568 and rs564481) in Klotho were selected to be genotyped in 1002 PE patients and 1384 normal controls with TaqMan allelic discrimination real-time PCR technology. There were no significant differences in genotypic or allelic frequencies at both polymorphic sites between PE patients and controls (rs1207568: chi(2) = 2.386, p=0.303 by genotype, chi(2) = 2.357, p=0.125, OR=1.127, 95% CI 0.968-1.312 by allele; rs564481: chi(2)= 1.195, p= 0.550 by genotype, chi(2)= 0.018, p= 0.894, OR= 1.010, 95% CI 0.875-1.165 by allele). Furthermore, we divided the cases into mild vs severe and early-onset vs late-onset subgroups and then analyzed the relationships between these subgroups and the control group respectively. As a consequence, no significant differences were found for both SNPs in each case. These results suggested that the genetic variants of rs1207568 and rs564481 in Klotho may not play a pivotal role in the pathogenesis of PE in Chinese Han women.