Definition
Cystic fibrosis (CF) is an inherited disease that causes glands throughout the body to make abnormally thick, sticky mucus. The most frequently affected organs include the lungs and pancreas. The intestines, liver, sweat glands, and reproductive organs also may be affected.
Cystic Fibrosis
Causes
CF is caused by two defective genes. A child inherits CF by inheriting one defective gene from each parent. Usually the parents do not have the disease but have a defective gene that can be passed on to the their children. These parents are called carriers.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
• Parents who are known carriers of the CF gene
• Siblings with CF
• Parents with CF
Symptoms
The abnormally thick mucus of CF blocks certain organs, causing many of the symptoms of CF.
Symptoms include:
• In infants:
o Difficulty passing the first stool (meconium)
o Meconium ileus, or intestinal obstruction (sometimes requires surgery)
• Trouble gaining weight
• Poor growth pattern
• Failure to thrive
• Malnutrition
• Bulky, bad-smelling, floating stools, due to poor digestion of fats
• Coughing and wheezing
• Repeated pneumonia
• Shortness of breath
• Difficulty with exercise
• Salty skin
• Abnormally shaped clubbed finger tips
• Barrel chest
• Nasal polyps
• Severe, chronic sinusitis
• Pancreatitis
• Insulin-dependent diabetes
• Gallstones
• Liver cirrhosis
• Mildly decreased fertility in females
• No sperm production in males
CF is a serious life-long condition that significantly reduces longevity and results in significant illness and ill-health for most affected individuals. Girls tend to be affected more severely than are boys. However, there is great variability in the severity of illness, and some persons with relatively mild forms of cystic fibrosis can live to age 60 or beyond.
Diagnosis
The doctor will ask about symptoms and medical history, and perform a physical exam. CF is suspected in a child with classic symptoms, especially if a sibling has CF.
Tests may include:
• Sweat chloride testing (still the standard for making a diagnosis of CF)
• DNA testing
• Nasal potential difference measurement
• Chest and/or sinus x-rays
• Tests of pancreatic function
• Lung function tests
• Newborn screening
Treatment
There is no treatment to cure CF. Treatment is aimed at:
• Preventing and treating lung infections
• Keeping the airways and lungs as clear as possible
• Improving nutritional status
Treatment for CF includes:
• Childhood immunizations
• Enzyme tablets with meals to improve digestion and absorption of nutrients
• Insulin shots if pancreas stops producing it
• High-calorie diet planned by a registered dietician
• Nutritional supplements, including fat-soluble vitamins
• Chest percussion and postural drainage or high-frequency chest wall oscillation (may help clear mucus from airways)
• Antibiotics to treat respiratory infections
• Medications to keep the airways clear, including:
o Theophylline (rarely used today)
o Bronchodilators
o Steroid inhalers
o DNase
o Acetylcysteine
o Nonsteroidal anti-inflammatory drugs (uncommonly used)
• Drinking lots of fluids, especially in hot weather or when ill
• Surgery (may be required to treat intestinal obstruction)
• Oxygen therapy (may be required as the disease progresses)
• Lung and liver transplants (possible)
Researchers are exploring gene therapy to slow the progression of CF, or even cure it.
Prevention
If you have the defective genes, there is no way to prevent the development of CF. Adults can be tested to see if they carry the defective gene before having children. Prenatal testing can determine if a baby will have CF, but the availability of this testing raises many important ethical questions.
