[1] Japanese Red Cross, Cent Blood Ctr, Shibuya Ku, Tokyo 150, Japan
[2] Wakunaga Pharmaceut Co Ltd, Inst Biotechnol Res, Hiroshima, Japan
[3] Univ Tokyo, Grad Sch Med, Dept Human Genet, Tokyo, Japan
[4] Univ Tokyo, Fac Med, Dept Transfus Med & Immunohematol, Tokyo 113, Japan