Science / Medicine : Discovery May Aid Early Cystic Fibrosis Detection

A new way to diagnose cystic fibrosis in children at an early age may result from a new understanding of the biochemical defect that causes the disorder, researchers from the Genzyme Corp. in Cambridge, Mass., reported last week in the journal Cell. The disease affects 30,000 people in the United States and is present in one in every 2,000 to 3,000 births.

The defective gene that causes cystic fibrosis was identified only last year. Now, molecular biologist Alan Smith and his colleagues at Genzyme have shown that, because of the defect, a membrane protein called cystic fibrosis transmembrane conductance regulator is misshapen. The cell’s internal quality control mechanisms thus discard the defective protein rather than deliver it to its normal location in the membranes of cells. As a result, salt builds up inside the cells.

Discovery of the protein’s function may lead to new drugs to mimic its activity, Smith said. Researchers will also now be able to screen for cystic fibrosis by detecting the presence or absence of the protein in the membrane, he added. Currently, genetic screening can be performed, but several defects in the same protein can cause the disease and it is necessary to screen for each one. Screening for absence of the protein would be much simpler.