Q. What is cystic fibrosis? A. Cystic fibrosis is a treatable disorder that affects the body's control of salt levels. It causes thick, sticky mucus to build up in the lungs and digestive system and other organs.
Q. What does it mean if my baby has an abnormal cystic fibrosis screen? A. It means that further testing is needed because your baby might have cystic fibrosis. Only about 1 in 3 babies with abnormal newborn screening results will actually have cystic fibrosis. However, it's important to find out soon because a baby who has cystic fibrosis will do much better if treatment begins early.
Q. How do I find out if my baby has cystic fibrosis? A. Another test, called a "sweat test", is needed to find out if your baby has cystic fibrosis. Performing this painless test on babies requires very special capability that is only available at Cystic Fibrosis Foundation accredited care centers.
Q. When can my baby have the sweat test? A. The sweat test is most reliable when the baby is two weeks of age or older, although it may be done earlier. Some babies will have inconclusive results and need to have additional testing.
Q. What are the effects of having cystic fibrosis? A. Cystic fibrosis causes thick, sticky mucus to build up in the lungs and digestive system and other organs of the body. This can lead to respiratory and digestive problems that can be very serious. Early detection and treatment is especially helpful to improve the digestive problems, growth and development.
Q. What is the treatment for cystic fibrosis? A. Treatments will vary depending on the baby, but will typically include special medicine to help the baby's digestion, a high-calorie, high-protein diet and special chest therapy. The best medical care for babies with cystic fibrosis is at care centers that are accredited by the national Cystic Fibrosis Foundation.
Q. Why would a baby have cystic fibrosis? A. Cystic fibrosis is an inherited disorder. It results when a baby receives a non-working cystic fibrosis gene from each parent. You can get more information about this from your health care provider or through the cystic fibrosis care center where the sweat test is done.
Q. How common is cystic fibrosis? A. About one in every 3,500 babies in the United States is born with cystic fibrosis.
Q. What is a "positive CFNBS" and what does it mean? A. It means that the immunotrypsinogen assay (IRT) tested in the upper 97.8% percentile for the day of the test. This triggered DNA analysis for the 46 most common cystic fibrosis genes in our population. That test was positive for at least 1 cystic fibrosis gene mutation. This test is only done on the first sample.
Q. Does that mean the patient has cystic fibrosis? A. That means that child possesses at least 1 common gene for cystic fibrosis gene mutation. It also means one of their parents also must carry the gene. Your patient is at least a carrier of one cystic fibrosis gene mutation.
Q. I thought you needed 2 gene mutations to have cystic fibrosis? A. This is true cystic fibrosis is an autosomal recessive disease. A child could have one common cystic fibrosis gene mutation and one uncommon cystic fibrosis gene mutation. Only the common cystic fibrosis gene mutation would be detected in the newborn screen. This panel of 46 common cystic fibrosis gene mutations accounts for about 92% of cystic fibrosis disease. At this time there are over 1400 known cystic fibrosis gene mutations. That's why the positive NBS needs further evaluation.
Further Reading