Genetic defects
Many people suffer from diseases caused by genetic defects. Using recombinant DNA techniques, scientists are able to test DNA isolated from cells of unborn babies to learn whether the babies will have a disease. Also, researchers have investigated methods of gene therapy in an effort to cure diseases. Such methods usually involve inserting normal genes from another individual or organism into a patient's cells outside the body and then returning these altered cells into the body.
Doctors first used gene therapy to treat a patient in 1990. The patient suffered from a weak immune system. Since then, numerous clinical trials using gene therapy on human beings have been undertaken. Gene therapy has been tested for use as treatment of many disorders, including cancer, cystic fibrosis, and the overproduction of cholesterol.
Excerpt from the "Genetic engineering" article, The World Book Encyclopedia © 1999