Cystic fibrosis (CF) is a genetic disease that causes breathing difficulties, chronic digestive problems, and other symptoms. It is caused by a gene mutation that causes thick, sticky mucus to build up in the lungs and other organs, causing damage over time.
Certain risk factors, such as being of European descent, increase your chances of developing cystic fibrosis. CF is relatively rare. It is estimated that approximately 38,000 people in the United States suffer from this condition.
CF is a chronic (long-term) progressive disease that gets worse over time and causes serious complications. Once considered a fatal disease for children, current treatment options and treatments have significantly improved the prognosis. Although life expectancy for CF is below average, many people with this condition are now living well into adulthood and enjoying a much better quality of life.
Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which regulates the production of the CFTR protein. The CFTR protein moves chloride ions out of cells, ultimately helping to balance salt and water in the body.
Researchers have identified more than 2,000 CFTR mutations, most of which fall into five classes.
- Type 1: Type 1 is caused by a genetic mutation that causes CFTR protein production to stop prematurely. This reduces levels of CFTR protein.
- Type 2: This is the most common type of mutation. Mutations change the shape of the CFTR protein by adding or subtracting amino acids. As a result, less protein can reach the cell and be activated.
- Type 3: The CFTR protein acts as a “gate” for the cell, allowing chloride (a component of salt) to pass through. The mutation limits its ability to open, trapping chloride inside.
- Type 4: The CFTR protein looks right, but it doesn't function properly. Chloride ions attract water and cannot leave the cells, making the mucus thicker.
- Type 5: This type occurs when a genetic mutation causes problems creating new CFTR protein.
Symptoms of cystic fibrosis vary from person to person. However, CF often causes distinct signs in newborns and infants, affecting organs such as the lungs, intestines, pancreas, etc.
Symptoms in Newborns and Infants
CF symptoms often appear within the first 6 to 8 months of life. Common signs include:
- abnormally salty skin
- Meconium ileus (inability to defecate for 24 to 48 hours after birth)
- throw up
- Fever
- redness and swelling
- Persistent jaundice (yellowing of the skin and eyes)
- Mucus from recurring lung infections and coughing
- Failure to grow and lack of weight gain
- Undescended testicles in babies assigned male at birth
respiratory symptoms
In adults, mucus buildup due to cystic fibrosis can have serious effects on the lungs, eventually leading to scarring, cyst formation, and lung failure. Respiratory symptoms include:
- wheezing
- chronic cough
- When coughing includes thick mucus or blood
- frequent lung or sinus infections
- Nasal polyps (growths within the nasal cavity)
digestive symptoms
Cystic fibrosis mucus can also spread to the intestines, liver, and pancreas (the organ just behind the stomach), causing a variety of symptoms, including:
- Constipation
- diarrhea
- greasy, foul-smelling stool
- excess mucus in stool
- Abdominal or back pain
- Nausea, vomiting, bloating
- Sudden weight loss, loss of appetite
- Jaundice (yellowing of the skin or eyes),
- dark urine
- light colored chair
- Fever
Other symptoms
Other organ systems in the body may also be affected, causing additional symptoms. These include:
- Male infertility due to abnormal development of the vas deferens
- Joint and muscle pain and swelling
- Digital clubbing (sticking out fingers or toes)
- Decreased lung function causes a bluish-purple tint to appear on the skin, often the lips, mouth, ear lobes, and fingernails
- Dandruff, itchy skin
Cystic fibrosis is caused by mutations in the CFTR gene, which regulates the formation of the CFTR protein. This protein moves chloride (salt ions) out of the cell, attracting fluid for lubrication. Mutations reduce this function, causing thick mucus to build up throughout the body.
Symptoms of cystic fibrosis are caused by excessive mucus buildup in organs, especially the lungs and digestive tract. This increases your risk of:
- Infection (because bacteria can easily get caught in mucus)
- Growths (cysts) and scar tissue (fibrosis) in the lungs
- Tissue damage and blocked tubes (openings) in the pancreas, liver, or intestines
risk factors
Cystic fibrosis is hereditary. In other words, it is caused by a genetic mutation that is passed down from parents to children. Therefore, a family history of cystic fibrosis is the only risk factor. The CFTR gene is recessive, so the disease only occurs if both parents have the disease. If you only have one, you won't have any symptoms, but you may still have the defective gene, which may increase your risk of passing cystic fibrosis to your children.
Other factors affect the severity of symptoms, including:
- Genetic mutations: The type of cystic fibrosis (type of CFTR mutation) affects severity. Grades 1 to 3 are more likely to become serious.
- Gyeongju: Cystic fibrosis affects 1 in 2,500 to 3,500 newborns of European descent. Other races or ethnicities remain at risk. It affects 1 in 17,000 African American and 1 in 31,000 Asian American newborns.
- Activity level: While higher levels of physical activity can improve lung health, an inactive lifestyle can lead to more severe cases.
- smoking: Because smoking cigarettes and breathing secondhand smoke affects lung function, exposure to smoke may worsen symptoms.
- age: CF is present at birth but gets worse with age. The older you get, the more likely you are to experience serious symptoms and complications.
Diagnosing CF typically involves several steps. Most cases are diagnosed within the first few days of life, especially as genetic testing and newborn screening become increasingly common.
The goal is to determine the cause of symptoms and rule out other conditions such as asthma, lung infections, celiac disease (inability to digest gluten), and other causes of growth failure.
Diagnosis may include:
- Genetic testing/carrier screening: This is a voluntary test to check your DNA and determine if you are a carrier of the defective CFTR gene. If you and your partner are carriers, your child has a 25% chance of developing cystic fibrosis.
- Pre-pregnancy or prenatal screening: You may choose to have a blood or saliva test for CFTR gene mutations before or during pregnancy.
- Universal newborn screening: Testing for CFTR mutations is now part of the standard screening panel for newborns in the United States. This is done through blood tests during the first 2 to 3 days of life. This checks for elevated levels of immunoreactive trypsinogen (IRT), which may be a sign of cystic fibrosis.
- Sweat Chloride Test: This test can confirm suspected cases or detect potential cases by testing for high chloride levels in sweat.
- Imaging: In some cases, your health care provider may use x-rays or other imaging methods to evaluate your lungs, abdominal cavity, and intestines.
There is no cure for cystic fibrosis, so the goals of treatment are to manage symptoms, support the function of the lungs and other affected organs, and prevent or manage related diseases or complications.
This involves a multifaceted approach guided by a specialized CF care team that includes pediatricians, pulmonologists (lung specialists), gastroenterologists (digestive system specialists), and nutritionists.
Airway Clearance Techniques
Airway clearance techniques (ACT) help loosen mucus so it can clear the lungs through coughing or gasping. Performing ACT helps manage mucus buildup in the lungs, improves lung function, and prevents infections.
Skills include learning specific techniques for breathing or coughing, using high-frequency chest wall vibration (a vibrating vest to loosen mucus), and performing chest physical therapy techniques.
prescription drugs
Most people with CF take a variety of medications. Medications may be used to help improve breathing, remove mucus, fight underlying infections, and/or improve CFTR protein function. These include:
- Antibiotics (oral or given intravenously (IV)) to fight bacterial infections
- Nonsteroidal anti-inflammatory drugs (NSAIDs), such as Advil (ibuprofen)
- Bronchodilators, inhaled medications that open and relax the airways
- CFTR modulators, including Kalydeco (ivacaftor), Orkambi (ivacaftor and lumacaftor), and Trikafta (elexacaftor, tezacaftor, and ivactafor)
- Digestive enzymes that help break down food and improve digestion
breathing support
If cystic fibrosis is seriously affecting your or your child's lungs, your health care provider may request breathing support devices and treatments, including:
- Oxygen therapy, which delivers oxygen through a face mask or tubes in the nose or windpipe (trachea)
- Pulmonary rehabilitation, a series of breathing and lung exercises supported by a physical therapist
- Ventilator support, which uses a device that introduces moist air into the lungs through a mask or breathing tube
- Extracorporeal membrane oxygenation, which pumps blood through an artificial lung to add oxygen and remove carbon dioxide, allowing the lungs to heal and recover.
surgery
In severe and advanced cases, surgery may be an option. Surgeons may perform a lung transplant in cases of lung failure due to cystic fibrosis. Liver transplantation is an option for liver failure, a potential but less common complication.
diet
For digestive symptoms of cystic fibrosis, health care providers recommend a balanced, high-calorie diet with the following characteristics:
- 2,500-3,000 calories per day for people assigned female at birth
- 3,000 to 3,700 calories for people assigned male at birth
- Foods that are very high in healthy fats, such as olive oil, avocados, and nuts
- Foods rich in protein and pancreatic enzymes that help the body absorb more nutrients from food
- Vitamins A, D, E
Because cystic fibrosis is a genetic disease, there is no way to prevent it. If you plan to become a parent, genetic testing can detect the mutated CFTR gene. This will help you find out whether you are likely to pass the disease on to your children or if you are a carrier.
Prenatal screening during pregnancy can detect many, but not all, types of cystic fibrosis. However, this type of test poses risks to the health of the fetus.
Cystic fibrosis can cause serious complications and increase the likelihood of developing many other conditions, including:
- ileus: Mucus from cystic fibrosis can block the intestines, which can be a medical emergency.
- gallstone: Accumulation can also block the cystic duct, forming gallstones (hard, pebble-like substances).
- Chronic respiratory failure: Mucus, scars, and cysts caused by cystic fibrosis can lead to respiratory failure, in which the lungs are unable to supply enough oxygen to the lungs and body.
- Cystic Fibrosis-Associated Diabetes: Diabetes, the inability to control blood sugar, is a complication that affects up to 50% of people with cystic fibrosis over the age of 30.
- Liver disease: Cystic fibrosis that spreads to the liver can cause liver failure (liver failure) and biliary cirrhosis (liver scarring due to blockage of the bile ducts).
- Pancreatitis: Another digestive complication is pancreatitis (inflammation and infection of the pancreas).
- malnutrition: The intestines absorb nutrients as part of digestion. Mucus from CF can affect this process, resulting in insufficient absorption of calories and nutrients.
When researchers first identified cystic fibrosis in 1938, newborns diagnosed were usually given about a year to live. With modern treatments and an improved understanding of genetics, about half of babies with the condition today may live into their 50s.
Promising treatments, including those targeting the CFTR gene, are also expected to become available soon. This could be a turning point in the management of cystic fibrosis. However, the emotional impact of living with this condition or being the parent of a loved one with this condition can be serious. Additional support strategies include: