Doctors cure boy in bubble

Pioneering gene therapy at London's Great Ormond Street Hospital appears to have cured a "bubble baby" born with no defence against infection.

The hospital revealed today that Rhys Evans, aged 18 months, was born with Severe Combined Immunodeficiency Disorder (SCID). Children with the condition have to be kept in completely sterile conditions - hence the term "baby in a bubble". Without treatment, such babies face death within a couple of years.

Last summer, Rhys's parents Mark and Marie, from South Wales, put him on the therapy programme and after intensive treatment he was already showing huge signs of improvement by Christmas.

A Great Ormond Street spokesman said: "In February, Rhys's blood results had made enormous progress and were almost normal. For the first time in his little life, he was allowed to start mixing with other children and playing outdoors, and has even just been on his first family holiday."

Rhys is the first baby in the UK to benefit from the work taking place at Great Ormond Street and its research partner, the Institute of Child Health.

Traditionally, SCID is treated by bone marrow transplants to provide the missing immune cells. In a healthy child, the cells are made from precursor stem cells in the bone marrow. The procedure has a high success rate when there is a matched brother or sister donor, and is modestly successful when the donor is a parent.

Nevertheless, only a third of children with SCID can be matched with a really good donor. The gene therapy technique being pioneered at Great Ormond Street is aimed at fixing the genetic fault that prevents a SCID child producing immune system cells.

During the procedure, bone marrow is removed from the patient and treated with a virus which carries the correct gene into the stem cells.

The corrected bone marrow is then infused into the child and allowed to generate immune cells which pass into the blood.

Doctors at Great Ormond Street are also looking at another immune system genetic disorder called Chronic Granulomatous Disease (CGD).

This affects neutrophils, a type of white blood cell responsible for destroying bacteria and fungi which invade the body.

Children with CGD have neutrophils but the cells do not work. As with SCID, the current treatment is a bone marrow transplant.

Because the disease involves immune cells which do not work, as opposed to not being there at all, all the bone marrow must be completely replaced - even with gene therapy.

X-CGD, the form of the illness which affects boys, is caused by a lack of the gene gp91phox.

Doctors administering gene therapy for the condition insert the gene in a sample of bone marrow removed from the patient. All the rest of the bone marrow has to be destroyed by chemotherapy before the corrected sample is replaced.

The new "Jeans for Genes" gene therapy laboratory at Great Ormond Street opened last year.

Jeans for Genes is a charity initiative that has raised more than £12million for research into children's genetic diseases since its launch in 1996. This year's target is at least an additional £2.5 million.

On Jeans for Genes Day, 4 October, thousands of people across the UK will wear jeans to work or school and donate £1 each to the appeal.

Even a cold could kill