Expression of the DCC gene was reduced or absent in 10 of 39 (26%) patients with acute myelogenous leukemia (AML), three of 14 (29%) patients with acute lymphocytic leukemia (ALL), seven of 33 (21%) patients with chronic myelogenous leukemia (CML), three of 39 (8%) patients with myelodysplastic syndromes (MDS), and five of nine (56%) patients with overt leukemia progressed from MDS.
We conclude that the Rb gene at 13q14, the Wilms tumour gene at 11p13, the DCC gene at 18q21, the neurofibromatosis 2 gene at 22q11-13 and uncloned tumour suppressor genes at 6q27, 8p21-22 and 11p15, as well as genes responsible for microsatellite instability, are unlikely to be involved in the progression of CML to blast crisis in the majority of patients.
Allelic loss in the DCC gene was observed in two patients (6%, 2 of 35 informative cases), and expression of the DCC gene was reduced or absent in 8 of 26 (31%) patients with acute myelogenous leukemia (AML), 3 of 9 (33%) patients with acute lymphocytic leukemia (ALL), and 7 of 29 (24%) patients with chronic myelogenous leukemia (CML).