Last Update: January 31, 2011.
Cystic fibrosis (CF) is the most common fatal genetic disease in the United States today. It causes the body to produce a thick, sticky mucus thatclogs the lungs, leading to infection, and blocks the pancreas, stopping digestive enzymes from reaching the intestines where they are required to digest food.
Building mouse models of human diseaseExpression of a human cystic fibrosis (CFTR) gene in the gut of a mouse. A human antisense probe was used to show human CFTR expressed in the mouse duodenum. Image reproduced with permission fromManson, A.L et al. (1997) EMBO J. 16, 4238-4249.
CF is caused by a defective gene, which codes for a chloride transporter found on the surface of the epithelial cells that line the lungs and otherorgans. Several hundred mutations have been found in this gene, all of which result in defective transport of chloride, and secondarily sodium, by epithelial cells. As a result, the amount of sodiumchloride (salt) is increased in bodily secretions. The severity of the disease symptoms of CF is directly related to the characteristic effects of the particular mutation(s) that have been inherited by thesufferer.
CF research has accelerated sharply since the discovery of CFTR in 1989. In 1990, scientists successfully cloned the normal gene and added it to CF cells in the laboratory, which correctedthe defective chloride transport mechanism. This technique—gene therapy—was then tried on a limited number of CF patients. However, this treatment may not be as successful as originally hoped. Furtherresearch will be required before gene therapy, and other experimental treatments, prove useful in combating CF.
Severe combined immunodeficiency
Severe combined immunodeficiency (SCID)represents a group of rare, sometimes fatal, congenital disorders characterized by little or no immune response. The defining feature of SCID, commonly known as "bubble boy" disease, is a defect in the...