Cystic Fibrosis and DNA Tests—The Implications of Carrier Screening

Abstract

Nearly 10 years ago, the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research speculated about the potential ethical, legal, and social consequences that might occur if a test were available to identify carriers for cystic fibrosis (CF) l , the most common, life-shortening, recessive genetic disease in American Caucasians. Time and technology have moved forward. The mysteries of biological inheritance-first explored by Austrian monk Gregor Mendel over a century ago-are yielding to modern science. A CF carrier test is no longer a prospect; it is now reality. The test's existence raises broad societal questions about the use of genetic information. And beyond CF tests, expectations of scores of additional genetic tests loom on the horizon as scientists in the United States and abroad pursue an ambitious mission to map and sequence the entire human genetic blueprint, or genome.Ongoing interest in the Human Genome Project, as well as concern about the potential magnitude and effects of routine CF carrier screening, led the House Committee on Science, Space, and Technology and the House Committee on Energy and Commerce to request an evaluation of the scientific, clinical, legal, economic, and social considerations of widespread carrier screening for CF. The study was also endorsed by Representative David R. Obey. Cystic Fibrosis and DNA Tests: Implications of Carrier Screening presents a range of options for action by the U.S. Congress in six broad policy areas:q genetics education and the public, q gentics training and education of health care professionals, q discrumination, . clinical laboratory and medical device regulation, q instrumentation to automate DNA diagnostics, and q integration of DNA assays into routine clinical practice.OTA prepared this report with the assistance of a panel of advisors and reviewers selected for their expertise and diverse points of view. Additionally, hundreds of individuals cooperated with OTA staff through interviews or by providing written material. These authorities were drawn from academia, industry, and professional societies, as well as Federal and State agencies. OTA gratefully acknowledges the contribution of each of these individuals. As with all OTA reports, however, responsibility for the content is OTA's alone.In publishing this report, OTA concludes that the value of the CF carrier test is the information it provides. No one can estimate in common terms what it means to an individual to possess information about his or her genetic status, especially when the value concerns reproductive decisionmaking. As our knowledge of the human genome increases, what we do with information such as CF carrier status will depend on the perceptions and beliefs of all Americans. We believe that public understanding of this new knowledge and its implications is necessary for its wise and thoughtful application.

Cystic Fibrosis Carrier Screening: ARE NURSES READY TO BE ON THE FRONT LINE?

“…CF is the most common severe autosomal recessive disorder among Caucasians, affecting approximately 30,000 Americans (Davis, Drumm, & Konstan, 1996). In the U.S., from 1,700 to 2,000 infants are born with CF annually, and the carrier frequency varies from 1 in 20 to 1 in 40 in different ethnic/racial populations (Nishimi, 1993). The median life expectancy of individuals with CF is about 30 years, and the disorder is incurable (Kuller, Baughman, & Biosli, 1999).…”

Comparison of Single-Entry and Double-Entry Two-Step Couple Screening for Cystic Fibrosis Carriers

“…© 1995 S. Karger AG, Basel l \ / -\ l \ V J t ' 0001-5652/96/0461-0020S8.00/0 E-Mail karger@karger.ch F ax+ 41 61 306 12 34 pies is supposed to have this l-in-4 risk with each pregnancy [ 1 ]. If couples with such a high risk are identified before birth or conception of a CF child, they can be informed about their high risk and consider all options, including prenatal diagnosis.…”

“…If couples with such a high risk are identified before birth or conception of a CF child, they can be informed about their high risk and consider all options, including prenatal diagnosis. In theory, the identifica tion of all at-risk couples can be achieved by population screening programs, and many pi lot studies are currently undertaken [4][5][6][7][8][9], The number of Americans of reproductive age who could theoretically be involved in CF carrier screening amounts to 125 million [1], With such high numbers, all possible strategies need to be carefully considered.…”

“…Cystic fibrosis (CF) is the most common life-shortening recessive disorder affecting people of European descent [1]. For instance, in the United States of America alone, 1,700-2,000 babies are born with CF annually [1], Disregarding rare instances of uniparental dis omy [2] or pseudodominance, both parents of CF patients are carriers of one mutated copy of the so-called CFTR gene [3], The number of Americans who are CF carriers is estimated to be 8 million [1].…”

“…For instance, in the United States of America alone, 1,700-2,000 babies are born with CF annually [1], Disregarding rare instances of uniparental dis omy [2] or pseudodominance, both parents of CF patients are carriers of one mutated copy of the so-called CFTR gene [3], The number of Americans who are CF carriers is estimated to be 8 million [1]. However, only children of couples where both partners are carriers are at a high l-in-4 risk of being affected with CF.…”