Objective: To investigate the relationship between human leukocyte antigen-G (HLA-G) gene Exon 8 14 bp deletion polymorphism and the pathogenesis of severe pre-eclampsia.
Methods: Forty-two pregnant women with severe pre-eclampsia, who admitted to the Third Affiliated Hospital of Zhengzhou University from October 2008 to February 2009, and their newborns were chosen as the severe pre-eclampsia group. Another 45 healthy gravidas at the third trimester and their newborns were chosen as the control. All gravidas in both groups were Han Nationality. HLA-G Exon 8 genotyping was detected by PCR in both groups and the allele frequencies and genotype frequencies were compared between the two groups. The genotype frequencies of maternal-neonatal pairs were also analyzed.
Results: (1) In the severe pre-eclampsia group, 14% of the maternal-neonatal pairs were homozygote of 14 bp deletion, and significantly higher frequency 33% (15/45) was found in the control group (P=0.038). (2) No significant difference was found in the allele frequencies and genotype frequencies of HLA-G 14 bp deletion polymorphism among all the mothers between the two groups (P>0.05). (3) The +14 bp and -14 bp allele frequencies of HLA-G 14 bp deletion polymorphism in newborns in the severe pre-eclampsia group were 44% (37/84) and 56% (47/84), respectively, and 30% (27/90) and 70% (63/90) in the control group. Although there was no significant difference between the two groups, but differences in trends was identified (chi2=3.678 P=0.055); The genotype (-14 bp/-14 bp) frequency of neonates in the severe pre-eclampsia group showed no difference compared with that in the control group [29% (12/42) vs 49% (22/45)], but differences in trends was also found (P=0.052).
Conclusions: HLA-G 14 bp deletion polymorphism is associated with the susceptibility of severe pre-eclampsia in Chinese Han nationality. Maternal-fetal genotype pairs of -14 bp/-14 bp may have reduced risk of severe pre-eclampsia.