The story of identical twins Olivia and Isabella made headlines around the world in 2008 after our scientists identified for the first time the cells that are the source of childhood acute lymphoblastic leukaemia (ALL).
Olivia was diagnosed with ALL in June 2005 when she was two but her sister, Isabella, did not develop leukaemia. As they are identical twins they share not just identical genes, but also shared the same placenta in the womb.
Scientists supported by Leukaemia & Lymphoma Research were able to study the twins. They found that both of them had the same genetically abnormal cells in their blood. These ‘pre-leukaemic’ stem cells reside in the bone marrow and either lie dormant or go on to develop into full-blown leukaemia stem cells.
The researchers were able to prove that pre-cancerous stem cells arise from an abnormal fusion of two genes during the mother’s pregnancy. This can set in motion a series of tiny molecular changes that cause cells to become leukaemic.
Now that our researchers have confirmed the existence of stem cells, the next step is to develop drugs to target the cancer stem cells and cure leukaemia while avoiding the potentially harmful side effects of current treatments.
Side effects can be serious. Olivia became blind in one eye as a result of an infection that her body was unable to fight due to the chemotherapy treatment. Thankfully though she is now in remission and doing well.
Olivia’s identical twin sister, Isabella, is 200 times more likely than other children to develop leukaemia because she is carrying the pre-leukaemic stem cell and is tested regularly.
Sarah Murphy, Olivia and Isabella’s mum, says: “I have always had Isabella to compare with so I could spot the differences easily when Olivia first developed ALL. We didn’t think twice about agreeing to take part in Leukaemia & Lymphoma Research's trial. Through comparing our twins’ blood, researchers have managed to isolate the pre-leukaemic cells that they had and to work out the reason why some children develop the disease.”