Cystic fibrosis (CF) is an autosomal recessive condition. This means that a person will have CF only if they receive the affected gene from both parents at conception.
Cystic fibrosis (CF) is a condition in which thick mucus causes damage to the lungs, the digestive system, and other organs throughout the body. CF is genetically inherited, which means it’s passed down through genes when sperm meets an egg.
CF is a disease that is inherited in an autosomal recessive manner. The word “autosomal” means that the affected gene is located on a numbered chromosome. “Recessive” means that a person must inherit affected genes from both biological parents to develop the disease.
So, autosomal recessive cystic fibrosis can be more simply referred to as cystic fibrosis. In CF, the secretions that are meant to protect and lubricate the organs — such as mucus, sweat, and saliva — become thick. They may cause blockages in different areas of the body, inflammation, and even infections.
Again, a person must inherit one affected gene from each parent to develop CF. Someone who inherits just one affected gene is considered a carrier of CF and can pass the gene to any children they conceive.
CF is caused by mutations to the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Changes to the CFTR gene affect the proteins that regulate chloride and sodium (salt) exchange between cells.
When this gene is affected, the normally thin and slippery secretions in the body become thick. Thickened secretions may block tubes, ducts, and other passageways to the organs throughout the body.
Signs and symptoms of CF may appear soon after a baby is born. The thick mucus can build up in a baby’s lungs. It can also make sweat and digestive fluids thicker, causing issues in other parts of their body.
Respiratory signs and symptoms may include:
- persistent cough
- cough with thick mucus or blood
- shortness of breath
- wheezing
- recurrent lung or sinus infections
- nasal polyps
Other possible signs and symptoms include:
- salty sweat (salty-tasting skin)
- failure to thrive
- constipation
- foul-smelling, greasy stools
- fertility issues
A doctor may diagnose CF by observing the signs and symptoms during a physical examination and taking a family history. In the United States, newborn screening for CF is typically performed with a simple heel prick within the first
To confirm the diagnosis, a doctor may suggest a sweat chloride test. During this procedure, doctors use a chemical combined with a weak electrical current to make the skin sweat. They then measure and analyze the sweat to look at its salt content. Saltier sweat may indicate that a person has CF.
Genetic (DNA) testing is another way to confirm a CF diagnosis. Doctors can use a blood test to look for CFTR mutations.
Treatment for CF can improve symptoms and quality of life, but it will not cure the disease. A person with CF may see several health professionals in different specialties (such as pulmonologists, dietitians, and respiratory therapists) to address symptoms of CF and the resulting complications.
Treatment includes:
- physical therapy to clear the airways and loosen mucus in the lungs
- chest devices (such as a mechanical vibrating vest) to loosen mucus in the lungs
- antibiotics to treat chronic lung infections such as pseudomonas infections
- dietary changes, such as adding enriched foods or vitamin supplements, to prevent malnutrition
- enzyme replacement therapy to treat pancreatic insufficiency
Two drugs specifically used to treat CF are Pulmozyme (to thin and clear mucus) and Kalydeco (to help with the movement of chloride in the cells). Other drugs used for CF include Orkambi, Symdeko, and Trikafta.
Severe CF may cause significant damage to the lungs. In these cases, a lung transplant may help but is carried out on a case-by-case basis.
The main risk factor for developing CF is having a history of the disease on both sides of your biological family.
CF is more common among white people but can affect anyone.
Until recent years, a child with CF typically did not live beyond childhood. But as a result of early screening and improved treatments, a child who receives a CF diagnosis today may live into their
What is an autosomal recessive disorder?
An autosomal recessive disorder is a condition that a person will develop only if they inherit affected genes from both parents during conception.
Does a lung transplant cure CF?
No. CF affects the way the cells transport chloride, causing thickened secretions that can damage the lungs. A lung transplant can address lung symptoms but cannot address the way the cells operate throughout the body.
What percentage of people carry the CF gene mutation?
According to the American Lung Association, about 30,000 people in the United States live with CF. Beyond that, around 1 in 30 people (3.3%) in the United States carry the gene for CF.
CF is an autosomal recessive condition inherited during conception. Doctors have made strides in the treatment of CF, and earlier detection and more advanced treatments have helped improve quality of life and extend life expectancy.
If you have a family history of CF and want to have biological children, talk with your doctor. You may want to consider genetic testing and genetic counseling to find out the chances that your child will have CF.