Treating genetic conditions
Once scientists have identified a gene, they can work out what it does in the body and what happens when it isn't working properly. Genes carry instructions that tell the body how to make different proteins. Some genetic conditions can be treated with a synthetic version of the missing protein: blood-clotting factors for haemophilia, for example. It may be possible one day to treat some genetic conditions by replacing the altered or missing gene, for instance for cystic fibrosis.