Cystic fibrosis is a chronic inherited disorder that has been the cause of suffering for children and adults throughout the history of the human race. It has a major impact on the lungs, digestive system, and reproductive organs. At first, the disease was not only misdiagnosed, but also it was believed to be a death-causing ailment, and it was even recognised through the attribute of salty skin in the folklore. It all started to get clear in 1949 when the researchers found that cystic fibrosis is due to defects in the CFTR protein, which is an essential chloride channel that helps in salt and water movement in the body. The mutations cause thick mucus, organ dysfunction, and repeated infections.As per the study published on PubMed Central, more than 2,000 mutations of the CFTR gene are identified. It also reveals that new therapies, such as CFTR modulators, have significantly extended the lifespan and enhanced the quality of life of many patients. This article further explains the condition as per the study.
Cystic fibrosis results from changes in a gene located on chromosome 7 that codes for the CFTR protein. The protein is a chloride channel that assists in maintaining the salt-water balance across epithelial surfaces. The condition arises only when the person has two defective copies of the gene. Scientists have discovered over 2,000 different mutations, and they are classified into five categories:Class I: No CFTR protein is made.Class II: Protein is made incorrectly and destroyed before reaching the cell surface. The most common mutation, ∆F508, belongs to this class.Class III: CFTR reaches the membrane but does not function properly.Class IV: The chloride channel works poorly.Class V: Reduced amounts of functional CFTR reach the cell surface.All result in reduced chloride secretion, increased sodium absorption, and thick, sticky mucus.
Who is affected ? Epidemiology
Cystic fibrosis is inherited through autosomal recessive and is frequently (about 1 in 3,500) observed in people of Northern European descent. Incidence of the disease is less in Black populations (1 in 15,000) and very rare in Asian populations (1 in 30,000). The ∆F508 mutation is the cause for almost 70% of the cases of White patients in the U.S. and about two-thirds of the cases worldwide. The patients carrying this mutation generally have pancreatic insufficiency and are predisposed to a higher risk of meconium ileus at birth.
How cystic fibrosis affects the body
Because CFTR affects many organs, the disease has widespread consequences:SinusesThick secretions block sinus openings, leading to chronic sinusitis, inflammation, and repeated bacterial colonisation, especially Pseudomonas aeruginosa.LungsLung tissue is normal at birth. After that, thick mucus causes blockage, infection, and inflammation. Eventually, this causes bronchiectasis, persistent sputum, airway obstruction, and respiratory failure and is the leading mortality in cystic fibrosis. Pancreas and LiverThick secretions block the pancreas from releasing enzymes into the intestines. Therefore, malabsorption, abdominal pain, and oily stools, as well as the deficiency of fat-soluble vitamins, occur. In severe cases, the disease may progress to pancreatitis or diabetes. Apart from that, thickened bile can also cause blockage of small ducts in the liver, which results in cirrhosis and portal hypertension. IntestinesNewborns may be presenting with meconium ileus. Children and adults may develop intestinal obstruction because of the dehydrated intestinal contents and pancreatic insufficiency.Sweat glandsDefective chloride reabsorption in sweat glands causes excessive sodium loss, resulting in characteristically “salty” skin and risk of dehydration.
Cystic Fibrosis: Signs and symptoms
Symptoms vary but may include:
- Chronic cough, bronchitis, and breathlessness
- Recurrent lung infections
- Poor weight gain or failure to thrive
- Sinusitis and nasal polyps
- Greasy stools and abdominal pain
- Infertility in males and reduced fertility in females
- Electrolyte imbalances
- Clubbing of fingers and skin changes due to nutritional deficiencies
Adults may also present with pancreatitis, liver disease, kidney stones, anaemia, or osteoporosis.
How cystic fibrosis is diagnosed
Diagnosis requires at least one clinical feature and one laboratory finding. Common diagnostic tools include:Sweat chloride test: Levels above 60 mEq/L strongly suggest cystic fibrosis.
- Genetic testing: Identifies two disease-causing CFTR mutations.
- Nasal potential difference testing: Used in complex cases.
- Newborn screening: Detects elevated immunoreactive trypsinogen (IRT).
Additional assessments such as chest radiographs, sputum cultures, pulmonary function tests, and abdominal imaging help determine disease severity.
Cystic Fibrosis: Treatment and management
Cystic fibrosis requires lifelong and multidisciplinary care. Key components include:Pulmonary Care
- Antibiotics for lung infections, especially P. aeruginosa.
- Inhaled bronchodilators and mucolytics such as dornase alfa.
- Chest physiotherapy to clear mucus.
- Oxygen therapy or noninvasive ventilation if needed.
- CFTR modulator therapies
These target the underlying protein defect:
- Ivacaftor for Class III mutations.
- Lumacaftor/ivacaftor for ∆F508 homozygous patients.
- Tezacaftor/ivacaftor combinations are showing promising safety profiles.
NutritionHigh-calorie diets, pancreatic enzyme supplements, and fat-soluble vitamins are essential. In severe cases, enteral feeding may be required.Advanced careIn comparison to medication, lung transplantation can prolong the life of a patient and also drastically improve the symptoms in case of respiratory failure.Cystic fibrosis is still a condition that will eventually lead to the death of the patient; however, due to modern drugs, early diagnosis, and specialised care, survival and quality of life have been significantly improved. Research into and production of more CFTR modulators are very promising for further advances in the coming years.(Disclaimer: This article is for general information only and is not a substitute for professional medical advice. Always speak to a healthcare professional for guidance based on your personal health and medical history.)
