Creation of Philadelphia chromosome

Most people with chronic myelogenous leukemia have a chromosome called the Philadelphia chromosome inside their blood cells. Typical cells each contain 23 pairs of chromosomes that are made of DNA. DNA holds the instructions for every cell in the body. The Philadelphia chromosome forms when chromosome 9 and chromosome 22 break and exchange parts. This creates a short chromosome 22 and a new combination of instructions for the cells. These new instructions can lead to the development of chronic myelogenous leukemia.

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