Children undergo gene therapy trials in London

The great potential of gene therapy to cure inherited diseases is under trial again. Some 10 children are undergoing treatment in a new gene therapy laboratory which officially opened in London earlier this week. The work is under way at Great Ormond Street children's hospital, which plans to offer the treatment to any family that requests it.

Genes are the working components of DNA. They produce proteins which are used to carry out essential biochemical functions in the body. Many inherited diseases are caused when mutated genes are passed on to a newborn. Errors in the gene cause the production of faulty proteins that don't work properly.

Gene therapy is an attempt to correct these errors, usually by the insertion of a fully functional gene inside a cell so that a missing protein can be replaced.

The Great Ormond Street team is attempting to treat two illnesses. One is "baby-in-the-bubble" syndrome, an inherited disorder in which the child lacks an effective immune system. The second is X-linked Chronic Granulomatous Disorder, a disease in which the white blood cells, which are central to the body's immune response, do not work properly.

Last year, a team of researchers in Paris became the first in the world to show that gene therapy can work in a clinical setting. They successfully treated two children with the bubble syndrome by inserting new genes into their bone marrow cells.

The UK team will take this further, using a partially inactivated virus to carry synthetic corrective genes into the children's cells. In both cases, a single treatment would be sufficient to deliver a lifetime cure, provided the system works.

Results of these trials should be available by the end of this year.