Fanconi anemia (FA) is an autosomal recessive inherited disorder with progressive bone marrow failure, associated congenital malformation and solid or hematological malignancies. Hematological symptoms usually appear between 4 and 14 years of age, however 10% of patients are older than
16 years of age at the time of diagnosis. Before the onset of the disease, both the morphology of the peripheral blood and bone marrow smears are within normal range. The first hematologic abnormalities may be thrombocytopenia, leukopenia with granulocytopenia, and anemia. The treatment of choice in children with FA and peripheral blood pancytopenia should be hematopoietic cell transplantation from the best compatible donor. Herein we report on a 12-year-old female patient, the first case in Poland, with FA who received combined cord blood and bone marrow transplantation from a sibling. Due to the risk of late graft rejection, donor lymphocyte infusion (DLI) was carried out twice. No clinical traits of graft vs. host disease (GvHD) were observed in the recipient and DLI resulted in a quantitative decrease in mixed chimerism. Now, more than two years after transplantation, the girl remains in a very good condition, with a normal hematopoietic function.