Cystic Fibrosis

Cystic Fibrosis


  • Cystic fibrosis is a life-threatening genetic disorder primarily impacting the lungs and digestive system.
  • It is caused by a mutation in the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene.
  • The disorder is autosomal recessive, meaning an individual must inherit two copies of the faulty CFTR gene – one from each parent – to develop the condition.


  • Symptoms include a persistent cough, frequent lung infections, inability to gain weight, and salty-tasting skin.
  • These are caused by a malfunction of the transmembrane proteins responsible for the transport of chloride ions.

CFTR Gene and Protein

  • The CFTR gene provides instructions for the CFTR protein, which acts as a channel for the transport of chloride ions across cell membranes.
  • A mutation in the CFTR gene disrupts this ion transport, leading to thick, sticky mucus in various organs.

Genetic Mutation

  • The most common mutation leading to cystic fibrosis is the delta F508 deletion (ΔF508), which removes a vital amino acid from the CFTR protein.
  • This disrupts protein folding, leading to its degradation and a lack of functioning CFTR channels on the cell surface.

Diagnosis and Management

  • Sweat tests and genetic screening are commonly used to diagnose cystic fibrosis.
  • Management techniques include physiotherapy to clear the lungs, medication to thin mucus, and dietary supplements to combat malnutrition.
  • Lung transplants may become necessary in severe cases.

Genetic Implications

  • Carriers of the cystic fibrosis gene mutation are generally healthy but can pass the faulty gene onto their offspring.
  • Couples with a family history of cystic fibrosis may seek genetic counselling to understand the potential risks to any future children.

Research and Future Directions

  • Researchers are exploring gene therapy as a method of correcting the defective CFTR gene in people with cystic fibrosis.
  • Drugs designed to improve the function of the mutated protein (CFTR modulators) hold promise for improving the quality of life for individuals with cystic fibrosis.