Gene Therapy

Gene therapy is the treatment of a disease or disorder by replacing, altering, or supplementing a gene that is absent or abnormal, where that absence or abnormality is responsible for the disease. A gene is simply a stretch of DNA needed to make a functional product, such as part or all of a protein; during gene therapy, DNA coding for the needed gene is delivered into the patient's individual cells.

Most, if not all, disorders have some genetic component. In some -- cystic fibrosis, haemophilia, muscular dystrophy -- a change in a single gene directly causes the condition; in others -- high cholesterol, high blood pressure -- genetic and environmental factors interact together to cause the disease. More than 5,000 different human genetic diseases are known to be caused by single-gene defects, including sickle-cell anaemia, thalassemia, Tay-Sachs disease, cystic fibrosis, Huntington's chorea, haemophilia, alkaptonuria and albinism. …