[Acute leukemia in two brothers].

A 42-year-old man was diagnosed as having refractory anemia in May, 2001. He developed overt leukemia and received allogeneic bone marrow transplantation (BMT). His younger brother, a 40-year-old man, was diagnosed as having acute leukemia with trilineage myelodysplasia in November, 2001. Although he was treated with conventional chemotherapy, he failed to achieve complete remission. He also received allogeneic BMT. We suggest that environmental factors in addition to a genetic defect in the pluripotent hematopoietic stem cells may be associated with the occurrence of this familial leukemia.