What is childhood acute myeloid leukaemia (AML)?

The word ‘acute’ means developing quickly. ‘Myeloid’ refers to myeloid blasts, the type of blood cell affected by the leukaemia.

All types of blood cells (white blood cells, red blood cells and platelets) are produced by blood stem cells in the bone marrow. Usually, the stem cells make as many blood cells as we need to stay healthy.

In AML, this system goes wrong. The stem cells start to produce too many blood cells, too quickly. These blood cells (known as myeloid blasts, or just blast cells) multiply too fast and don’t develop properly. Because they aren’t fully developed, they can’t do the job they were made for and they don’t die when they should.

The abnormal blast cells (leukaemia cells) overcrowd the bone marrow and spill out into the bloodstream. They can be carried in the blood to other areas of the body where they stop other cells working properly.

We don’t know what causes childhood AML. We do know that changes happen in the genes of cells in the bone marrow.

Genes are a set of instructions that tell individual cells how to behave, and errors in these instructions mean cells can’t function properly.

There’s nothing you could have done to stop your child developing AML. It’s not possible to ‘catch’ AML from someone else and it isn’t passed from parent to child.

There are some things that make it more likely to develop AML:

• age – AML is most common in adults, particularly in later life. AML in children and teenagers is rare but seen slightly more often in children under the age of four.
• previous treatment for cancer – Having anti-cancer drugs for another type of cancer can cause what’s known as therapy-related AML. This rarely affects children.
• Down’s syndrome – Children with Down’s syndrome are more likely to develop a particular type of AML.

The Down’s Syndrome Association has more information about Down’s syndrome and leukaemia.