Castelli, E. C., Mendes-Junior, C. T., Deghaide, N. H. S., de Albuquerque, R. S., Muniz, Y. C. N., Simões, R. T., Carosella, E. D., Moreau, P., and Donadi, E. A.
The HLA-G gene is predominantly expressed at the maternal–fetal interface. It has been associated with maternal–fetal tolerance and in the inhibition of cytotoxic T lymphocyte and natural killer cytolytic functions. At least two variations in the 3′untranslated region (UTR) of HLA-G locus are associated with HLA-G expression levels, the 14-bp deletion/insertion polymorphism and the +3142 single-nucleotide polymorphism (SNP). However, this region has not been completely characterized yet. The variability of the 3′UTR of HLA-G gene and its haplotype structure were characterized in 155 individuals from Brazil, as well as HLA-G alleles associated with each of the 3′UTR haplotype. The following eight variation sites were detected: the 14-bp polymorphism and SNPs at the positions +3003T/C, +3010C/G, +3027A/C, +3035C/T, +3142G/C, +3187A/G and +3196C/G. Similarly, 11 different 3′UTR haplotypes were identified and several HLA-G alleles presented only one 3′UTR haplotype. In addition, a high linkage disequilibrium among the variation sites was detected, especially among the 14-bp insertion and the alleles +3142G and +3187A, all previously associated with low mRNA availability, demonstrating that their effects are not independent. The detailed analyses of 3′UTR of the HLA-G locus may shed some light into mechanisms underlying the regulation of HLA-G expression. [ABSTRACT FROM AUTHOR]