What is Cystic Fibrosis?

Written by Aarushi Rai

Cystic Fibrosis is an inherited genetic disorder that affects more than 100,000 people worldwide. It can cause severe damage to the lungs, the digestive system, and other organs. Because there is no complete cure for CF and the disease is progressive, it requires daily care, but many people with it now are able to lead relatively normal lives, in stark contrast to decades ago when very little was known about cystic fibrosis. Next, let's take a closer look into symptoms, causes, and possible treatments for CF. 

Cystic fibrosis is genetic, meaning that people with it inherited it from their parents. Both their parents must have had at least one copy of the defective CF gene. While their parents may not have had CF themselves (making them a carrier), if both have a copy of the defective gene, then their children have a ¼ chance of not getting CF, a ½ chance of becoming a carrier but not affected by the disease itself, and a ¼ chance of getting cystic fibrosis. There are mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) that cause the CFTR protein to become dysfunctional. Because of this, the protein cannot help move chloride to cell surfaces, and without the chloride to attract water to the surface, mucus in cells and thus organs become sticky and thick. This mucus then goes on to plug and block tubes, ducts, and passageways within the body. The affected cells produce mucus, sweat, and digestive juices, causing symptoms and issues in the digestive system, liver, and respiratory system for those with CF. There are more than 1700 mutations of the CF disease. 

Signs and symptoms of cystic fibrosis vary from person to person depending on which type of mutation they have inherited. Some common symptoms and signs of CF, however, include respiratory, digestive, and liver symptoms. For the respiratory system, a persistent cough along with thick mucus and blood, frequent lung infections and inflammation in the nasal passages are all common. Because of how easily those with CF can get infections, inflammation, and have respiratory failure, avoiding germs is extremely important for them. For the digestive system, the thick mucus can also block the tubes that bring digestive enzymes to the small intestine from the pancreas. This can be very harmful because without these digestive enzymes, the intestines will not be able to completely absorb the necessary nutrients from food, consequently leading to malnutrition and poor growth. Lastly, liver symptoms can also develop because of the thick mucus blocking the bile duct and causing liver disease, among other illnesses. In general, CF traps germs and makes infections much more likely in a person. 

Despite all this, research has made significant leaps in treatments to help relieve or prevent certain symptoms. These include things like therapy for airway clearance to loosen or get rid of the mucus buildup in the lungs or in extreme cases, lung transplants. Many people use inhaled medicines for this airway clearance, which include antibiotics to fight lung infections. Usually, a combination of these various therapies is most beneficial to one with Cystic Fibrosis. Additionally, pancreatic enzyme supplement capsules that help with improving the absorption of nutrients taken with meals, as well as CFTR modulators that can target the specific defect in the CFTR protein. However, with the CFTR modulators, they have been developed for specific mutations and thus are only effective in people with those specific mutations, as different mutations cause different defects in proteins. Even outside of treatments, carrier screening can be done before pregnancy or during pregnancy. Newborn screening is also done for all babies in the USA to check for CF immediately after birth in order to begin treatment and to delay or prevent complications and symptoms if a baby has CF. 

References

Cystic fibrosis - Symptoms and causes - Mayo Clinic. (2021, November 23). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/cystic-fibrosis/symptoms-causes/syc-20353700

About cystic fibrosis. (n.d.). Cystic Fibrosis Foundation. https://www.cff.org/intro-cf/about-cystic-fibrosis

About cystic fibrosis. (2024, May 15). Cystic Fibrosis. https://www.cdc.gov/cystic-fibrosis/about/index.html

Written by Aarushi Rai