A 14-member nongovernmental panel convened by NIH in April 1997 recommended that genetic testing for mutations that cause cystic fibrosis (CF) be offered to all pregnant couples, those planning a pregnancy, those with a family history of the disease, and partners of people with CF. The panel did not endorse genetic testing of newborns because current research does not show a benefit.

The panel made its recommendations at the close of a 3-day NIH Consensus Development Conference on Genetic Testing for Cystic Fibrosis. The Consensus Development Program was established in 1977 as a "science court" mechanism to resolve controversial topics in medicine and public health in an unbiased, impartial manner. The conference was sponsored by the NIH Office of Medical Applications of Research and the National Human Genome Research Institute.

CF, the most common inherited disorder in Caucasians, occurs when a child inherits two mutated copies of the CF gene, one from each parent. CF symptoms include lung, pancreatic, and intestinal complications ranging from mild to severe. Genetic testing for CF in adults usually involves identifying healthy carriers'people who have a single copy of the mutated gene and will never develop the disease. They are at risk of having a child with CF if their partner is a carrier.

Although more than 600 mutations have been identified in the CF gene, a single mutation (delta-F508) accounts for about 70% of CF alleles in Caucasians, 48% in African-Americans, 46% in Hispanics, and 30% in Asian-Americans and Ashkenazi Jews. Many CF gene tests are designed to detect about 70 of the most common mutations; by combining detection of delta-F508 with other mutations common to specific ethnic groups, it is possible to achieve 90% to 95% specificity for some ethnic groups, panel members explained. Few correlations have been made between particular mutations and disease severity.

The panel emphasized the importance of education, counseling, and informed consent for all genetic testing. "As more and more genetic tests for a variety of diseases become available, it is important for both healthcare providers and patients to understand the limitations and implications of such tests," said panel chair R. Rodney Howell (University of Miami School of Medicine).