Menu   WellSpan Health

Health Library

Health Library

The Genetics of Cystic Fibrosis

Cystic fibrosis (CF) is a genetic disease. This means that CF is inherited. A child will be born with CF only if two CF genes are inherited--one from the mother and one from the father. A person who has only one CF gene is healthy and said to be a carrier of the disease. A carrier has an increased chance of having a child with CF.

Once parents have had a child with CF, they have a one in four, or 25 percent chance, that each additional child will be born with CF. This means that there is a three out of four, or 75 percent chance, that additional children will not have CF. However, these children may be carriers of the CF gene.

Because most often a family has no history of CF, the diagnosis comes as a surprise to parents. Since both parents are healthy, they had no prior knowledge that they carried the gene, or that they passed the gene to the pregnancy at the same time.

Genes are found on structures in the cells of the body called chromosomes. Each cell normally contains 46 total, or 23 pairs of chromosomes. The seventh pair of chromosomes contains a gene called the cystic fibrosis transmembrane regulator (CFTR) gene. Mutations or errors in this gene are what cause CF. This gene is quite large and complex. More than 1,800 different mutations in this gene have been found that cause CF.

According to the Cystic Fibrosis Foundation, the risk for having a mutation in the gene for CF depends on your ethnic background if you have no family history of CF:

Ethnic Background

Risk of CF Mutation

Risk of Child with CF

Caucasian

1 in 29

1 in 2,500-3,500

Hispanic

1 in 46

1 in 4,000-10,000

African-American

1 in 65

1 in 15,000-20,000

Asian

1 in 90

1 in 100,000

A sweat chloride test to measure the amount of salt in your sweat is usually the first test done to try to diagnose CF.

Testing for the CF gene can be done from a small blood sample or from a cheek swab, which is a brush rubbed against the inside of your cheek to obtain cells for testing. Laboratories generally test for the 20 or so most common mutations.

Many people with CF have mutations that have not been identified. In other words, all of the genetic errors that cause the disease have not been discovered. Because not all mutations are detectable, a person can still be a CF carrier even if no mutations were found by carrier testing.

Testing for the CF gene is recommended for anyone who has a family member with the disease, or whose partner is a known carrier of CF or affected with CF.

The Genetics of Cystic Fibrosis - WellSpan Health

Online Medical Reviewer: MMI board-certified, academically-affiliated clinician
Online Medical Reviewer: Sather, Rita, RN
Last Review Date: 2014-10-13T00:00:00
Last Modified Date: 2014-12-01T00:00:00
Published Date: 2014-12-01T00:00:00
Last Review Date: 2007-03-30T00:00:00
© 2015 WellSpan Health. All Rights Reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.

×

Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to www.mywellspan.org, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.

×