In the rare condition, known as severe combined immunodeficiency (SCID), inherited genetic mutations mean that babies are unable to fight off infection, severely limiting their chances of surviving more than a few years.

However, researchers have now unveiled results of trial that show that gene therapy was successful in 14 out of the 16 UK children they treated, allowing them to recover to lead normal lives. The technique works by introducing a working copy of the mutant gene, which provides the body with instructions on how to produce working immune system cells. The child followed for the longest time, nine years, still had functioning immune cells, showing that gene therapy works in the long-term. More ……