Core binding factor acute myeloid leukemia

A rearrangement (translocation) of genetic material involving the RUNX1T1 gene is found in approximately 7 percent of individuals with a form of blood cancer known as acute myeloid leukemia (AML). This translocation, written as t(8;21), combines genetic information from chromosome 8 and chromosome 21, fusing a gene called RUNX1 on chromosome 21 with the RUNX1T1 gene on chromosome 8. When associated with this translocation, the condition is classified as core binding factor AML (CBF-AML).

The protein produced from the normal RUNX1 gene is part of a protein complex known as core binding factor (CBF). As part of CBF, the RUNX1 protein attaches to specific areas of DNA and turns on (activates) genes that are involved in the development of blood cells. Like RUNX1, the fusion protein produced from the t(8;21) translocation, called RUNX1-ETO, attaches to DNA; however, because ETO is involved, the fusion protein turns off genes related to blood cell development instead of turning them on. This change in gene activity blocks the maturation (differentiation) of blood cells and leads to the production of abnormal, immature white blood cells called myeloid blasts. While t(8;21) is important for leukemia development, one or more additional genetic changes are typically needed for the myeloid blasts to develop into cancerous leukemia cells.