Variation in the HLA-G promoter region influences miscarriage rates.

Published

Journal Article

The HLA-G gene is primarily expressed in placental cells that invade the maternal decidua during pregnancy. This gene encodes multiple isoforms that fulfill a variety of functions at the maternal-fetal interface throughout gestation. Recently, a null allele for the most abundant HLA-G isoform was associated with recurrent miscarriage in two independent studies, suggesting that reduced levels of the HLA-G1 protein may compromise successful pregnancy. We initiated the present study to determine whether other polymorphisms that could affect expression levels of HLA-G were associated with fetal loss in women participating in a 15-year prospective study of pregnancy outcome. We genotyped these subjects for 18 single-nucleotide polymorphisms in the 1,300 bp upstream of exon 1, 13 of which were identified as part of this study, as well as for an insertion/deletion (in/del) polymorphism in the 3' untranslated region. The 18 SNPs defined eight unique haplotypes. One polymorphism, -725C/G, was associated with fetal loss, with an increased risk for miscarriage in couples in which both partners carried the -725G allele, compared with couples not carrying this allele (odds ratio 2.76, 95% confidence interval 1.08-7.09; P=.035). Further, the G at nucleotide -725 creates a CpG dinucleotide, and we demonstrate that this CpG site is methylated on -725G alleles. Overall, this study identified extraordinary levels of variation in the 5'-upstream regulatory region of HLA-G and provides evidence for an association between a promoter-region SNP and fetal loss rates, further attesting to the novel features and critical role of this gene in pregnancy.

Full Text

Cited Authors

  • Ober, C; Aldrich, CL; Chervoneva, I; Billstrand, C; Rahimov, F; Gray, HL; Hyslop, T

Published Date

  • June 2003

Published In

Volume / Issue

  • 72 / 6

Start / End Page

  • 1425 - 1435

PubMed ID

  • 12721954

Pubmed Central ID

  • 12721954

International Standard Serial Number (ISSN)

  • 0002-9297

Digital Object Identifier (DOI)

  • 10.1086/375501

Language

  • eng

Conference Location

  • United States