What Causes Acute Lymphocytic Leukemia?
Between 1973 and 1990, the number of acute lymphocytic leukemia cases in children under 15 rose by 27%. The causes of the disease are not known, but experts believe that ALL develops from a combination of genetic and environmental factors. Genetic Factors A number of genetic mutations associated with ALL have been identified. Missing or defective genes that suppress tumors are responsible for some of these cases. Translocations. Up to 65% of leukemias contain genetic rearrangements, called translocations, in which some of the genetic material (genes) on a chromosome may be altered, or shuffled, between a pair of chromosomes. • For example the most common genetic injury in ALL is t(12;21), which means a translocation with a genetic shift between chromosome 12 and 21. It is also referred to as TEL-AML1 fusion and occurs in approximately 20% of ALL patients. Researchers believe that this translocation may occur during fetal development insome patients. • About 20% of adults and about 5% o
