Mol. Hum. Reprod. Advance Access originally published online on October 24, 2008
Molecular Human Reproduction 2008 14(11):649-653; doi:10.1093/molehr/gan059
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A single base-pair mutation in the 3'-untranslated region of HLA-G mRNA is associated with pre-eclampsia
1Department of Obstetrics and Gynecology, Sunnybrook Health Sciences Centre and Womens College Hospital, University of Toronto, Toronto, Ontario, Canada M5G 1N8 2Core Laboratory, Sichuan Academy of Medical Sciences, Sichuan Provincial Peoples Hospital, Chengdu, Sichuan 610072, People's Republic of China
3 Correspondence address. 790 Bay Street, Suite 1100 Toronto, Ontario, Canada M5G 1N8. Tel: +1-416-323-7727; Fax: +1-416-323-7334; E-mail: cliffl{at}ican.net
Human leukocyte antigen-G (HLA-G) is a non-classical class I HLA molecule that is expressed by extravillous cytotrophoblast cells. This protein may play a critical role in the protection of cytotrophoblasts from maternal immune response, allowing these semi-allogeneic cells to invade the uterus unimpeded. We have demonstrated that diminished placental HLA-G expression is associated with pre-eclampsia. In order to explore fundamental mechanisms underlying this reduced HLA-G expression in pre-eclampsia, we looked for, and found by sequences analysis, a single base-pair mutation in the HLA-G gene 3'-untranslated region (3'UTR) adjacent to an AUUUA motif. This mutation is significantly associated with pre-eclampsia, the severe form being more strongly associated with homozygosity for this mutation than the mild form. Since the null allele was discovered in the HLA-G mRNA 3'UTR adjacent to an AUUUA motif, we also examined the effect of this mutation on HLA-G mRNA stability, and found that half-lives of HLA-G mRNA with the mutation were significantly shorter than without the mutation. These data provide evidence that this mutation could be one of the fundamental mechanisms for lower levels of placental HLA-G protein expression in patients with pre-eclampsia.
Key words: HLA-G/gene mutation/RNA stability/pre-eclampsia
Submitted on May 5, 2008; resubmitted on September 22, 2008; accepted on September 24, 2008.