Gene Mutation for Cystic Fibrosis in Newborns (Blood)
Does this test have other names?
Genetic test for cystic fibrosis
What is this test?
This is a blood test that screens newborn babies for cystic fibrosis (CF), one of
the most common genetic diseases in the U.S. Most cases of CF are diagnosed in babies
before their first birthday, and often in the newborn period if there is an abnormal
CF is a potentially life-threatening condition in which your glands secrete abnormally
thick mucus that harms different systems in your body, including the airways and pancreas.
People with CF tend to develop chronic lung disease and lung infections. They may
also have persistent coughing, wheezing, and sinus infections.
In people with CF, digestive enzymes from the pancreas also have trouble reaching
the small intestine. For this reason, people with CF often have trouble digesting
food and absorbing nutrients properly. Symptoms in children can also include a swollen
belly, bad-smelling stools, poor growth, and salty-tasting skin.
Why does my child need this test?
This test is often part of routine newborn screening, although the exact tests vary
What other tests might my child have along with this test?
In newborns, this test is often done along with other tests for possible endocrine,
hematologic, or metabolic conditions.
What do my child's test results mean?
Test results may vary depending on your child's age, gender, health history, the method
used for the test, and other things. Your child's test results may not mean your child
has a problem. Ask your healthcare provider what the test results mean for your child.
For CF to happen, a child must inherit one abnormal copy of the CF gene from each
parent. That is, he or she must have two copies of the defective gene. Some people
may have just one abnormal copy of the CF gene, making them carriers without having
Most states now screen all newborns for CF, among other diseases. Different states
check for different mutations in children if the newborn screening raises a concern.
These genetic tests can look for as many as 70 mutations responsible for more than
90% of CF cases.
How is this test done?
This test needs a blood sample. In a newborn, this is done by pricking the child's
heel to obtain a few drops of blood.
What might affect my child's test results?
Because the test looks at genetic material, your child's actions don't affect the
results of this test.
How does my child get ready for this test?
Your child doesn't need to prepare for this test. Be sure your healthcare provider
knows about all medicines, herbs, vitamins, and supplements your child is taking.