Vascular endothelial growth factor +936C/T and -634G/C polymorphisms exhibited significantly different allelic distributions and no associations with the risk of preeclampsia, gestational hypertension or gestational diabetes mellitus in the Xinjiang Uygur Autonomous Region of China

Background: The relationships between vascular endothelial growth factor (VEGF) + 936C/T and − 634C/G gene polymorphisms and certain diseases have been widely reported. According to reported data, there may be geographical and/or ethnic differences in VEGF + 936C/T and − 634C/G allele frequencies. Xinjiang is a multi-ethnic region in China in which the distributions of the + 936C/T and − 634C/G allele frequencies in various ethnic groups and their correlations with common complications during pregnancy (preeclampsia (PE), gestational hypertension (GH) and gestational diabetes mellitus (GDM)) have not been studied. Methods: A total of 2161 women (1551 controls with normal pregnancy, 232 patients with PE, 59 patients with GH and 319 patients with GDM) were recruited for this study. Sanger sequencing was used to screen VEGF + 936C/T and − 634C/G genotypes. The Pearson chi-square test was used to test the associations between diseases and + 936C/T and − 634C/G polymorphisms. Results: We investigated the distributions of VEGF + 936C/T and − 634G/C allele frequencies in healthy pregnant women in different regions of the world and found significant differences. Our data showed that the distributions of + 936C/T and − 634G/C allele frequencies between healthy Han and Uygur women in the Xinjiang area were significantly different. We found that VEGF + 936C/T and − 634G/C gene polymorphisms were not correlated with mild PE (mPE), severe PE (sPE), GH or GDM. Ethnic subgroup analysis revealed that the + 936C/T and − 634G/C gene polymorphisms in the Han, Uygur and Hui populations were also not related to PE, GH or GDM. Conclusions: The results showed that VEGF + 936C/T and − 634G/C gene polymorphisms had significant regional and ethnic distribution differences. In Xinjiang, VEGF + 936C/T and − 634G/C gene polymorphisms do not confer susceptibility to PE, GH or GDM.