What are the causes for Acute lymphoblastic leukemia, adult?

The exact cause of adult acute lymphoblastic leukemia is not known, although chromosomal abnormalities in lymphoblast cells can lead to the uncontrolled growth observed in this type of blood cancer. The initiating factor that creates the abnormal chromosome is not known, but genetic and environmental factors may both play a role. In particular, radiation exposure or therapy for a prior cancer can create DNA mutations that lead to the chromosome abnormality.

Source: http://www.rightdiagnosis.com