CFTR Proteins and Defects

What are CFTR proteins and what do they do?

CFTR proteins are found on the surface of some cells in your body, for example, the cells that line the airways in your lungs. Normal CFTR proteins act like channels on the surface of the cells. They open and close to let chloride ions move into and out of the cell—a process called “gating.” This helps maintain a healthy balance of salt and water in the tissues.

Normal CFTR proteins

Proteins that work as they should allow chloride ions to pass into or out of the cells.

Clear Airway

Little particles called chloride ions move into and out of the cells through CFTR protein channels to help keep a balance of salt and water in the lungs. Mucus stays thin and watery, so the lungs can work well.

What are some of the defects that may affect the lungs?

A mutation (a change) in the CF gene may make CFTR proteins that don’t work correctly. This results in the “gates” of the CFTR proteins staying closed most of the time.

Because the “gates” are closed, very few chloride ions move into or out of the cell. This changes the balance of salt and water in the lungs, causing thick, sticky mucus to build up and affect how your lungs work.


How do defects in CFTR proteins affect my lungs?

A mutation may make defective proteins that don't work correctly or don't get to the cell surface, where they are normally located. CFTR protein defects can cause CF. Different mutations result in different defects.

Clogged Airway

When CFTR proteins don’t work the way they should, very few chloride ions are able to move into or out of the cells. Thick, sticky mucus builds up and affects how the lungs work.


What is KALYDECO® (ivacaftor)?

KALYDECO is a prescription medicine used for the treatment of cystic fibrosis (CF) in patients age 2 years and older who have at least one mutation in their CF gene that is responsive to KALYDECO.

Talk to your doctor to learn if you have an indicated CF gene mutation.

It is not known if KALYDECO is safe and effective in children under 2 years of age.

Important Safety Information

Who should not take KALYDECO?

Do not take KALYDECO if you take certain medicines or herbal supplements such as: the antibiotics rifampin (Rifamate®, Rifater®) or rifabutin (Mycobutin®); seizure medications such as phenobarbital, carbamazepine (Tegretol®, Carbatrol®, Equetro®) or phenytoin (Dilantin®, Phenytek®); or St. John’s wort.

Talk to your doctor before taking KALYDECO if you take any of these medicines or supplements.