Gene therapy trials in London hospital

Great Ormond Street Hospital in London has a brand new laboratory which will be used for research into genetic diseases and especially gene therapy for sick children. The new unit is partly funded by the Jeans for Genes campaign and the Institute for Child Health.

The clinic hopes to start trials aimed at immune system defects. A form of gene therapy that reprogrammes faulty immune systems will be tested in 10 babies with two different immune system diseases that are potentially fatal. Five of the babies in the trial have a type of severe combined immunodeficiency (SCID). These children are sometimes known as 'babies in bubbles' - because they produce no lymphocytes to fight infections they have to be isolated from the world.

The version of the disease being treated in the trial is X-SCID, a single gene disorder affecting only boys. The other disease to be treated is X-linked Chronic Granulomatous Disorder (X-CGD). This causes the production of phagocytes - bacteria and fungus fighting cells - to be faulty.

The London trials will use a similar technique to that used by a Paris team last year, which successfully modified the genes of children with SCID, restoring the immune system of four out of five children. The London team will extract the bone marrow of the babies, insert healthy genes into some of the bone marrow stem cells, and then transfuse the marrow back into the babies.