- Standard-risk patients who are under age 20 and achieve CR after day 80 are assigned to arm IV of group A. Patients who achieve CR after day 80 and have a genotypically or phenotypically HLA-matched family donor, a family donor mismatched at only 1 locus (A, B, or DR), or an HLA-matched unrelated donor proceed to group B. Patients who achieve CR after day 80 and are eligible for autologous bone marrow transplantation (BMT) proceed to group A. Patients found to be at extremely high risk are taken off study.