The HLA-G 14bp gene polymorphism and decidual HLA-G 14bp gene expression in pre-eclamptic and normal pregnancies.

Trophoblast expression of the non-classical MHC, HLA-G, is considered essential for feto-maternal immune tolerance and successful placentation in pregnancy. The HLA-G 14bp polymorphism in the 3'-untranslated region (UTR) of the HLA-G gene has been reported to be associated with development of pre-eclampsia (PE). In this study, maternal (peripheral blood, n=54) and fetal (cord blood, n=57) HLA-G 14bp genotypes have been determined by PCR in pre-eclamptic and normal pregnancies. In addition, HLA-G 14bp gene expression in decidua basalis (n=59) was analyzed by RT-PCR. The pre-eclamptic syndrome was neither associated with the HLA-G 14bp genotype (maternal or fetal), nor with altered decidual HLA-G 14bp gene expression. Furthermore, the HLA-G 14bp mRNA expressed in decidua basalis was of fetal origin and all potential transcripts, as predicted from the fetal HLA-G 14bp genotype, were expressed. In contrast to previous findings, we found no correlation between the HLA-G 14bp polymorphism and fetal growth. In conclusion, the fetal HLA-G 14bp genotype is reflected in the decidual HLA-G mRNA splice form profile, but does not appear to be associated with increased risk for development of PE.