Screening For Cystic Fibrosis
Cystic fibrosis is an inherited disease affecting the lungs and digestive system. The disease process involves changes in the chemical properties of mucous within these organ systems resulting in frequent /chronic lung infections, diabetes requiring insulin and problems with digestion and nutrient absorption. Persons affected by cystic fibrosis have a shortened life-span.
There is no mental impairment with cystic fibrosis. A child inherits this disease from his or her parents. In order for this to happen, each parent must be a carrier for the cystic fibrosis gene. Persons who are carriers for cystic fibrosis do not have symptoms of the disease. Cystic fibrosis occurs when the child receives a copy of the disease-producing gene from each parent.
The American College of Obstetricians and Gynecologists (ACOG) recommends offering cystic fibrosis testing to patients with a family history of the disease, high risk groups such as persons of eastern/northern European descent or Ashkenazi Jewish background, and to Caucasian couples. Even though there may be no family history of cystic fibrosis, the only way to know if you are a carrier of the gene is by performing a simple blood test.
A parent is considered a carrier for cystic fibrosis if the abnormal gene is identified in his or her serum. If both parents are found to be carriers for the disease there is a 25% chance they will have a child with cystic fibrosis and a 50% chance their child will be a carrier. The only way to know if a fetus is affected with cystic fibrosis is by performing an amniocentesis.
Diagnostic testing (amniocentesis) is offered only to couples who have both been identified as cystic fibrosis carriers. There is no treatment available for the fetus if the diagnosis is confirmed by amniocentesis and amniocentesis has a small risk of pregnancy loss. Some couples want to know if the fetus is affected so they may prepare themselves for having a child with special medical needs while other couples need to know this information in order to make decisions regarding future pregnancy or pregnancy termination. Both the blood test to determine cystic fibrosis carrier status and the amniocentesis for diagnosis are optional tests.
Deciding whether to have screening for genetic disorders is up to you and your partner and is a personal decision for which there are no right or wrong answers. Cystic fibrosis carrier testing is associated with a very low rate of false positive results. The carrier test will rarely have a false negative result. Currently available testing detects the genes responsible for producing 90% of cystic fibrosis cases. Check with your insurance carrier prior to testing to see if the test will be covered. Cystic fibrosis carrier testing costs approximately $350.00. Please review the ACOG pamphlet, and if you desire further information on this disease, visit the Cystic Fibrosis Foundation at www.cff.org.