The last decade has seen extraordinary advances in identifying single genes that are responsible for a variety of human diseases. Most recantly researchers have pinpointed the genes that cause retinoblastoma, chronic granulomatous disease, muscular dystrophy, and cystic fibrosis, the last as recently as September. Ingenious experimental design and new technologies are helping to pave the way for rapid identification of other disease-causing genes. And from there, the development of improved diagnostic procedures and therapeutic treatments is sure to follow, say experts.
For most genetic diseases, the normal function of the involved gene is not known. Localizing a disease-causing gene without knowing anything about the disease’s molecular or biochemical nature is , called “reverse genetics.” The process of identifying such genes is laborious, since there are between 50,000 and 100,000 genes distributed within 3 billion base pairs of DNA. But recently developed techniques are greatly expediting such searches for the proverbial...