Lack of association between glutathione S-transferase M1 and T1 gene polymorphisms and susceptibility to preeclampsia: An updated systematic review and meta-analysis

Associations of FOXP3 gene polymorphisms with susceptibility and severity of preeclampsia: A meta-analysis

OBJECTIVE

FOXP3 single nucleotide polymorphisms (SNPs) were recently elucidated to influence the development of preeclampsia (PE), but the results on this issue still remained controversial. Thus, a meta-analysis was implemented to systematically investigate the roles of FOXP3 SNPs in PE.

METHODS

Eligible publications were identified by retrieving relevant electronic databases. Meanwhile, the association intensity was estimated by calculating odds ratios (ORs) and 95% confidence intervals (CIs) in various genetic models.

RESULTS

Totally eight investigations involving 3446 subjects were enrolled in the final meta-analysis. The AC and AC + CC genotypes of FOXP3 rs3761548 were related to the susceptibility of PE in over-dominant (OR = 1.19, 95%CI = 1.02-1.38, P = 0.03) and recessive (OR = 0.59, 95% CI: 0.36-0.97, P = 0.04) models. Furthermore, correlation between rs2232365 and PE was observed in recessive model (GG vs. GA + AA) (OR = 0.79, 95%CI: 0.65-0.97, P = 0.03). Moreover, rs2232365 GA and GG + GA genotypes were associated with the severity of PE. However, rs4824747, rs3761547 and rs2280883 polymorphisms had no significant impact on PE susceptibility.

CONCLUSIONS

FOXP3 rs3761548 and rs2232365 SNPs influenced the PE susceptibility and therefore may be potential biomarkers for prediction of PE risk.

GSTM1 and GSTT1 polymorphisms in healthy volunteers - a worldwide systematic review

The GSTM1 and GSTT1 genes encode homonymous enzymes, which are responsible for the detoxification of several substances potentially harmful to the human body, such as air pollution, drugs, pesticides, and tobacco. However, some individuals may present a complete deletion of these genes and, consequently, an enzyme deficiency leading to an inadequate metabolism and, therefore, a higher susceptibility to some clinical conditions. Interethnic variations have also been described for both genes, making necessary the study of the deletion frequencies of GSTM1 and GSTT1 in different populations around the world. So, the aim of this study was to enable the synthesis and discussion of the main population differences of GSTM1 and GSTT1 polymorphisms in healthy volunteers. Searches were performed in the PubMed database, including 533 articles and 178,566 individuals in the analyses. We found an overrepresentation of European individuals and studies, and an underrepresentation of non-European ethnicities. Moreover, there are significant frequency differences among distinct ethnic groups: East Asians present the highest frequencies worldwide for GSTM1 and GSTT1 deletions, which could suggest higher disorders risk for this population; in contrast, Sub-Saharan Africans presented the lowest frequency of GSTM1 worldwide, corroborating evolution inferences performed previously for other genes codifying metabolism enzymes. Also, admixture is a relevant component when analyzing frequency values for both genes, but further studies focusing on this subject are warranted.