AJRI 2001; 45:168 – 173 Printed in Ireland - all rights resered. Polymorphism of Human Leukocyte Antigen-E Gene in the Japanese Population with or without Recurrent Abortion TAKAO KANAI, TOMOYUKI FUJII, NAOTO KEICHO, KATSUSHI TOKUNAGA, TAKAHIRO YAMASHITA, HIRONOBU HYODO, AKINORI MIKI, NOBUYA UNNO, SHIRO KOZUMA, AND YUJI TAKETANI Kanai T, Fujii T, Keicho N, Tokunaga K, Yamashita T, Hyodo H, Miki A, Unno N, Kozuma S, Taketani Y. Polymorphism of human leukocyte antigen -E gene in the Japanese population with or without recurrent abortion. AJRI 2001; 45:168 – 173 © Munksgaard, Copenhagen PROBLEM: The aim of this study was to investigate the gene frequencies and shared alleles of human leukocyte antigen (HLA)-E gene in Japanese couples with or without recurrent abortion. METHOD OF STUDY: Polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis was carried out to detect polymorphism in exon 3 of the HLA-E gene in 30 Japanese couples with recurrent abortion and 38 normal Japanese couples with proven fertility. RESULTS: No point mutation was detected in exon 3 of HLA-E in both recurrent aborters and normal controls. HLA-EG and HLA-ER alleles were detected with frequencies of 66.7% and 33.3% in couples with recurrent abortion and 69.2% and 30.8% in normal couples, respectively. The gene frequency of HLA-EG was higher than that of HLA-ER, which is contrary to that found in Caucasian, African–Amer- ican and Hispanic people but similar to Chinese people. The frequency of each allele was not significantly different between recurrent aborters and normal controls. The number of shared alleles between each couple with recurrent abortion is not signifi- cantly different from that with normal controls. CONCLUSION: Allele frequencies of HLA-E were suggested to be different in Asian people from those in other ethnic people. In light of no specific distribution pattern in recurrent aborters, HLA-E polymorphism does not seem to play a role in the pathogenesis of recurrent abortion. Key words: Human leukocyte antigen-E, polymorphism, recurrent abortion, trophoblast TAKAO KANAI TOMOYUKI FUJII TAKAHIRO YAMASHITA HIRONOBU HYODO AKINORI MIKI NOBUYA UNNO SHIRO KOZUMA YUJI TAKETANI Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, Tokyo, Japan NAOTO KEICHO Department of Respiratory Medicine, Faculty of Medicine, University of Tokyo, Tokyo, Japan KATSUSHI TOKUNAGA Department of Human Genetics, Graduate School of Medicine, University of Tokyo, Tokyo, Japan Address reprint requests to Tomoyuki Fujii, Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655 Japan. E-mail: fujiit-tky@umin.ac.jp Submitted May 30, 2000; revised July 24, 2000; accepted July 28, 2000. © MUNKSGAARD, COPENHAGEN