A French teenager’s sickle cell disease has been reversed using a pioneering treatment to change his DNA (BBC News, 2017). The world first procedure at Hôpital Necker – Enfants Malades in Paris offers hope to millions of people with the blood disorder.

Sickle cell is a lifelong condition caused by a faulty gene that affects how red blood cells develop. These deformed blood cells, which are shaped like sickles, can lock together to block the flow of blood around the body. This can cause intense pain and organ damage, and can be fatal. Sickle cell mainly affects people of African, Caribbean, Middle Eastern, Eastern Mediterranean and Asian origin. People with sickle cell disease are often at an increased risk of contracting serious infections or they could become anaemic. This can cause tiredness and shortness of breath. Some patients have regular blood transfusions, usually every three to four weeks, as a form of treatment for the condition.

The boy who received the treatment had so much internal damage he needed to have his spleen removed and his hips replaced. Every month he had to go into hospital to have a blood transfusion to dilute his defective blood. But when he was thirteen doctors at the Hôpital Necker removed his bone marrow. They then genetically altered it in a lab to compensate for the defect in his DNA that caused the disease. Sickle cell is caused by an error in the instructions for making haemoglobin. A virus was used to infect the bone marrow with new, correct instructions. The corrected bone marrow was then put back into the patient.

The results in the New England Journal of Medicine showed the boy has been making normal blood since the procedure fifteen months ago.

Philippe Leboulch, a professor of medicine at the University of Paris, said “So far the patient has no sign of the disease, no pain, no hospitalisation. He no longer requires a transfusion so we are quite pleased with that. But of course we need to perform the same therapy in many patients to feel confident that it is robust enough to propose it as a mainstream therapy.” Philippe Leboulch is nervous about using the word “cure” as this is just the first patient to come through clinical trials. But the study does show the potential power of gene therapy to transform the lives of people with sickle cell.

Dr Deborah Gill, from the gene medicine research group at the University of Oxford, said “I think it’s very significant, essential they’ve given him his life back. I’ve worked in gene therapy for a long time and we make small steps and know there’s years more work. But here you have someone who has received gene therapy and has complete clinical remission – that’s a huge step forward.”

However, the expensive procedure can only be carried out in cutting-edge hospitals and laboratories, while most people with sickle cell disease live in Africa.