IT SOUNDS like science fiction, and for years it seemed as though it was just that: fiction.
But the idea of gene therapyâintroducing copies of healthy genes into people who lack them, to treat diseaseâis at last looking as if it may become science fact.
The field got off to a bad start, with the widely reported death of an American liver patient in 1999. In 2003 some French children who were being treated with it for an immune-system problem called SCID developed leukaemia. Since