The peak age incidence is between 40-60 years. Typical presenting symptoms include fatigue, anorexia, and weight loss. Splenomegaly can be seen in up to half of patients.
Most patients progress from chronic phase to a fatal blast crisis in five years.
Three different fusion gene products, depending on the breakpoint in the bcr gene, have been reported. ALL express Philadelphia chromosome. Half of them express the 210 kD fusion protein, while the other half express the 190 kD one. When used to follow patients after bone marrow transplantation for CML, a negative result predicts longer disease free survival. A positive result, however, does not predict imminent relapse.