Newborn Screening and Genetic Testing

Newborn Screening — Newborns screened for cystic fibrosis can benefit from early diagnosis and treatment, which can:

• Improve growth;
• Help keep lungs healthy;
• Reduce hospital stays; and
• Add years to life

While newborn screening is not a definitive diagnostic test for cystic fibrosis, it may lead to tests that can rule out or confirm a CF diagnosis. All states in the U.S. screen newborns for cystic fibrosis.

In New Jersey, all newborns are screened with 1-2 days after birth. Results of the newborn screen will be sent directly to your pediatrician along with recommendations for repeat or referral if screen was positive. A positive newborn screen is NOT a diagnosis of Cystic Fibrosis. Usually the screen is repeated and if the second screen is also positive, you and your child should be referred to an accredited CF Center for further testing.

Genetic Testing

When a patient is referred to our center for testing, we may order a few genetic tests to look for the presence of two CF causing mutations.

Only about one of every 3,000 Caucasian newborns has CF. We know there are more than 1,800 known mutations of the gene that causes CF. However, not all mutations cause CF. The ones that do cause CF are called "disease-causing" mutations. Current tests look for the most common disease-causing mutations.

More than 10 million Americans are carriers of one mutation of the CF gene. Among Caucasian Americans, about one in 29 people carry one mutation of the CF gene. In other races or ethnicities, one in 46 Hispanic Americans, one in 65 African Americans and one in 90 Asian Americans carry a mutation of the CF gene.

People inherit (or get) genes from their parents. To have CF, a child must inherit one copy of a mutation of the CF gene from each parent. In other words, the child must have two copies of the gene with mutations to have CF. Both males and females can have the disease.

People who have only one copy of the CF gene do not have. They are called "carriers" of the CF gene.

The chances of being a carrier of one CF mutation or having CF (with two CF disease-causing mutations) depend on your race and ethnicity. CF gene mutations are most common in Caucasian Americans (white people whose ancestors or family are from Europe).

In the U.S., the number of people who carry a CF gene is about:

• 1 in 29 Caucasian Americans;
• 1 in 46 Hispanic Americans;
• 1 in 65 African Americans; and
• 1 in 90 Asian Americans.

In the U.S., the number of people who have CF is about:

• 1 in 2,500–3,500 Caucasian Americans;
• 1 in 4,000–10,000 Hispanic Americans;
• 1 in 15,000–20,000 African Americans; and
• 1 in 100,000 Asian Americans.

For more information about carrier testing and the Genetics of CF, go to http://www.cff.org/AboutCF/Testing/