[Diminished in vitro colony forming capacity of bone marrow cells in a case of chromosome 8 trisomy (mosaicism): criteria for "high risk" pre-leukemia syndrome].

A case has been described of Trisomy 8 mosaicism Syndrome. At onset the child presented with hyporegenerative anemia; the study of colony forming capacity in vitro (CFU) by Bone Marrow (B) and Peripheral Blood (PB) showed an abnormal colony formation by myeloid and erythroid progenitor cells. No immunological defects were discovered. The in vitro colony formation appears to have a definite role in the identification of patients who may be at higher risk of developing leukemia. The importance of 8 chromosome for hematopoiesis control is discussed.