Cystic fibrosis corrected in lab

Article Abstract:

Cystic fibrosis is the most common fatal genetic disease in North America. The gene that is defective in patients with cystic fibrosis was identified last year. This gene regulates production of a protein known as the cystic fibrosis transmembrane conductance regulator (CFTR), which forms a channel, or opening, involved in the transport of chloride ions out of cells. In cystic fibrosis, the channel is closed and the chloride ions cannot leave the cells, resulting in a buildup of thick mucus in the lungs. Two groups of researchers have successfully inserted the normal gene into defective cells. This allowed the channel to function normally. The two groups achieved the gene transfer using different methods, but both approaches used a virus which had been genetically engineered to carry the normal CFTR gene. One group was led by James Wilson and Francis Collins of the University of Michigan and by Raymond Frizzel of the University of Alabama, Birmingham. The researchers inserted the normal gene into a virus, known as a retrovirus, which infected pancreatic cells obtained from a patient with cystic fibrosis. The virus carrying the normal gene inserted itself into the chromosomes of the cell and produced the CFTR protein. The second group, led by Michael Welsh at the University of Iowa, Alan Smith of Genzyme Corporation (Framingham, Massachusetts), and Douglas Jefferson of Tufts University, inserted the gene into airway epithelial cells using another virus, the vaccinia virus. The transfer of the normal gene into defective cells, and the curing of the defect, is the first step in the possible treatment of cystic fibrosis by gene therapy. In gene therapy, genes that are normal are inserted into individuals with a particular genetic disease, so that the normal genes can function properly and prevent or cure the disease. It is thought that the use of gene therapy to treat cystic fibrosis patients may be only years away, not decades away as was previously believed. It is envisioned that the method of administering the gene into patients could be the use of a type of aerosol containing the normal gene, which the patient would inhale. (Consumer Summary produced by Reliance Medical Information, Inc.)

Care and treatment, Gene therapy, Genetic engineering

---

CF screening delayed for awhile, perhaps forever

Article Abstract:

Cystic fibrosis is the most common lethal genetic disease, affecting 1 in 2,500 newborn children. Enthusiasm for a diagnostic test to screen couples quickly waxed a year ago when the mutant gene in some cases of cystic fibrosis was identified. Subsequently it was found that this gene identified roughly 75 percent of the carriers of cystic fibrosis, that is, 75 percent of the people who carry a single copy of the mutant gene and risk having children with cystic fibrosis should they marry another carrier. The next step seemed simple: find the mutation that accounts for the remaining 25 percent and it's time to start testing. Unfortunately, the initial enthusiasm has waned considerably. As researchers in the field gathered new mutations by visiting new families, they discovered 20 new mutations before they had covered a few percent of the cystic fibrosis families. Researchers are now faced with the disturbing prospect that there may be hundreds of different mutations, any of which may lead to cystic fibrosis. If this turns out to be the case, a practical test would be difficult or impossible. Of course, researchers might still find a single mutation which accounts for most of the remaining 25 percent, a find that would guarantee a practical genetic screening test. Unfortunately it is beginning to seem as though cystic fibrosis might turn out to be like muscular dystrophy, with many individuals having their own idiosyncratic mutations. While some investigators feel that an incomplete genetic screening test is better than nothing, others suggest that supplying people with inadequate information about their risks of having an unhealthy child may be worse than no advice at all. (Consumer Summary produced by Reliance Medical Information, Inc.)

Usage, Genetic disorders, editorial

---

To test or not to test?

Article Abstract:

Cystic fibrosis (CF) is an inherited disease that affects the pancreas, lungs, and sweat glands. It begins in infancy and is characterized by chronic lung infection, abnormal function of the pancreas, and a high salt content in sweat. Although one in 25 whites carries the gene that determines cystic fibrosis, this gene is recessive and each parent must pass on the gene before the disease is expressed in their offspring. CF affects one in 2,000 whites and one in 17,000 blacks. There is no cure, but antibiotics have been used to increase the survival rate of affected individuals. In August 1989, Lap-Chee Tsui and Francis Collins identified a gene defect that occurs in about 70 percent of all CF carriers. This prompted the development of a genetic test that would screen individuals for the presence of the defective CF gene. However, several problems were anticipated with genetic screening for CF. The genetic defect identified by Tsui and Collins does not account for all cases of cystic fibrosis, and thus genetic screening for CF is not as yet 100 percent definitive. Once a definitive test is available, there will be questions about how, who and when to screen for CF. Programs for education and counseling must also be developed before genetic screening for CF. In addition, the test is currently too expensive for widespread screening. Until these problems can be resolved, genetic screening has been limited to academic genetic centers and private genetic practices. These questions must be addressed soon, to prevent lawsuits against those who do not offer the test.

Social aspects

Similar abstracts:

• Abstracts: Chemical analysis of diesel engine nanoparticles using a nano-DMA/thermal desorption particle beam mass spectrometer
• Abstracts: Superfund research program threatened by Congress, EPA. States, ASTM developing standards for voluntary cleanups
• Abstracts: The promise of the mother cell. Growing replacement parts. Code of the code
• Abstracts: Constitutive modeling of cold compaction and sintering of hardmetal. Constitutive data for powder compaction modeling
• Abstracts: Fetal tissue transplants remain off limits. Fetal research. Fetal research ban on shaky ground?

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.