Successful transplantation of ethnically mismatched cord blood in a boy with atypical chronic myeloid leukemia.

In the present study, we describe unrelated umbilical cord blood transplantation (CBT) in a 7-year-old Taiwanese boy with atypical chronic myeloid leukemia (BCR-ABL 1 negative). Physical examination was notable for splenomegaly. Cytogenetic analyses from the bone marrow revealed a t(3;5)(p21;q31) translocation. The patient then underwent CBT from an HLA-mismatched (two loci by serotype, three loci by genotype) unrelated donor of Caucasian origin. Times to neutrophil and platelet engraftment were 21 and 62 days post-transplant, respectively. Acute graft-versus-host disease following transplantation was minimal. The patient remains in continuing hematological remission with full donor chimerism 28 months after transplantation.