Analysis of human leukocyte antigen-G polymorphism including intron 4 in Japanese couples with habitual abortion.

PROBLEM

The purpose of this study was to clarify whether there is a difference between the allele frequency of human leukocyte antigen (HLA)-G in healthy Japanese people and that of Japanese couples with habitual abortion.

METHOD OF STUDY

Exons 2, 3, 4, and intron 4 of the HLA-G gene were analyzed in 20 couples with habitual abortion, using polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis. Intron 4 of the HLA-G gene was also analyzed in 54 healthy individuals. The nucleotide sequence of the PCR product of intron 4 was further determined by direct sequencing.

RESULTS

Two kinds of nucleotide sequence were identified in intron 4 of the HLA-G gene, one of which was identical to that of HLA-G01011, and the other was identical to that of HLA-G01012, G01013, and G0104. The frequency of each allele in affected women and their husbands did not significantly differ from that of healthy individuals, and no mutation was found in any affected couple.

CONCLUSION

HLA-G allelic abnormality seemed to have little, if any, implication in the pathogenesis of habitual abortion.