Chronic myeloid leukaemia (CML)

CML is rare, occurring in 1 in 100,000 people, most commonly in middle-aged people. All patients have the same genetic disorder in their bone marrow which they have acquired during their lifetime (and therefore have not inherited). It involves an exchange (a translocation) of parts of chromosome, between chromosomes 9 and 22. In this way, the BCR and ABL genes come to lie next to each other, creating a receptor that emits a constant growth signal.

This leads to excess white blood cells in the blood, which take over the healthy cells and thus threaten normal functions.