What is cystic fibrosis?

Cystic fibrosis is a relatively common genetic condition in which the lungs and digestive system become clogged with thick, sticky mucus.

Multiple mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene on chromosome 7 cause cystic fibrosis.

The most prevalent genetic defect that leads to cystic fibrosis is the deletion of three DNA bases (a codon) from the CFTR gene.

Cystic fibrosis is a recessive genetic condition, which means that both copies of a person's CFTR gene must be mutated for the disease to develop.

A person is considered a carrier if they possess a single copy of the mutant gene. Approximately one in twenty-five people are carriers for cystic fibrosis.

Cystic fibrosis has the highest incidence of any recessive disease (about 1 in 2,000) in Caucasian populations, but is less prevalent in other ethnic groups.

Cystic fibrosis transmembrane conductance regulator protein is encoded by the CFTR gene (CFTR).

The CFTR protein functions as a channel across the membrane of specialised cells that generate mucus, perspiration, saliva, tears, and digestive enzymes.

This protein channel ordinarily transfers chloride ions into and out of these cells, so regulating the movement of water in tissues and preserving the fluidity of mucus in our lungs and other bodily systems.

The most prevalent genetic defect that causes cystic fibrosis is the absence of one amino acid from the CFTR protein channel.

This alteration inhibits the movement of chloride ions and water into and out of cells, hence disrupting the function of the CFTR chloride channel.

The accumulation of thick, sticky mucus in the lungs and respiratory tubes causes coughing and chronic breathing difficulties, which are the most prevalent symptoms of cystic fibrosis.

Recurrent lung infections are quite frequent, and can result in fibrosis, or lung scarring, in the long run.

The airways of the lungs are harmed by this fibrosis and heavy mucus. In turn, this results in an increased propensity for infections and diminished lung function.

In 85% of cases of cystic fibrosis, patients also have a pancreatic insufficiency due to thick mucus clogging the pancreatic ducts. This stops the pancreas from releasing digestive enzymes and creating insulin, which can result in diabetes. Children with this feature of the condition struggle to gain weight and suffer from malnutrition.

Almost all males with cystic fibrosis are infertile due to the absence of sperm-transporting tubes (vasa deferentia).

In families with a history of cystic fibrosis, prenatal testing for the mutant version of the CFTR gene can also be performed.

In the absence of a family history, symptoms of the disease may include extremely salty-tasting sweat, frequent lung infections, and a slowed growth rate.

A simple test that analyses the quantity of salt in sweat can be used to diagnose cystic fibrosis since people with the disease have extremely salty perspiration.

There is no cure for cystic fibrosis, but there are treatments and medications that make living with the disease easier. Patients with the illness may benefit from daily physiotherapy. Drumming and stroking the patient's back and chest helps to loosen and rid the lungs of mucus. This decreases the likelihood of contracting lung infections.

Also, mucus-thinning medications may be provided. To identify lung infections, careful surveillance is necessary. Antibiotics, such as tobramysin (typically inhaled as a vapour), are frequently administered to treat infections and to prevent infections throughout life.

Helping patients whose pancreas is clogged with mucus by supplementing the diet with enzymes normally produced by the pancreas to aid in food digestion is possible when the pancreas is blocked with mucus.

Gene therapy tries to repair or replace faulty CFTR genes with functional copies. Although these treatments for cystic fibrosis have not yet proven helpful, this is an intriguing field of research.

Initially, the typical life expectancy after a diagnosis of cystic fibrosis was 14 years. The life expectancy of people with cystic fibrosis has drastically increased over the past few decades, with many surviving into adulthood in very good health.