What are the other Names for this Condition? (Also known as/Synonyms)

• CF (Cystic Fibrosis)

What is Cystic Fibrosis? (Definition/Background Information)

• Cystic Fibrosis (CF) is a genetic condition that affects the CFTR protein in the body. Individuals with CF have a faulty protein that affects the body’s cells, tissues, and glands that make mucus and sweat. The condition is inherited in an autosomal recessive pattern
• Mucus is normally slippery and protects the linings of the airways, digestive tract, and other organs and tissues. Individuals with Cystic Fibrosis produce thick and sticky mucus that can buildup and lead to blockages, damage, or infections in the affected organs
• Some individuals with Cystic Fibrosis have few or no signs or symptoms, while others experience severe symptoms or life-threatening complications. The sign and symptoms also depend on which organs are affected. The condition may be diagnosed through genetic studies and sweat chloride tests
• The most serious but common complication of Cystic Fibrosis involves the lungs, resulting in serious lung infections and respiratory issues. Individuals may also present growth delays since they have difficulty absorbing the nutrients from food
• The management of Cystic Fibrosis depends on the severity of the condition and the organs involved. The treatments may include measures to improve lung function and prevent/manage complications. Early and appropriate treatment can help improve one’s quality of life

The known mutations in Cystic Fibrosis are divided into five classes, based on the functional abnormality in the CFTR protein, with the identified genes divided by class.

• Class I Production Mutations (genes G542X, W1282X, R553X)
• Class II Processing Mutations (genes F808del, N1303K, 1507del)
• Class III Gating Mutations (genes G551D, S549N)
• Class IV Conduction Mutations (D1152H, R347P, R117H)
• Class V Reduced Quantity Mutations (genes 3849+10kbC>T, 2789+5G>A, A455E)                                           

Who gets Cystic Fibrosis? (Age and Sex Distribution)

• Cystic Fibrosis is a congenital condition that is manifested at birth
• It is most commonly observed in individuals with Northern European ancestry and is less common in Hispanics and African Americans. The condition is also relatively uncommon in Asian Americans
• Both males and females are affected, and no gender predilection is noted

What are the Risk Factors for Cystic Fibrosis? (Predisposing Factors)

The following can increase the risk for developing the condition:

• A positive family history of the condition
• Being a descendent of North European ancestry

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Cystic Fibrosis? (Etiology)

Cystic Fibrosis (CF) is an inherited condition caused by mutations in an agene called the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The mode of inheritance of CF is autosomal recessive.

• The CFTR gene provides instructions for the CFTR protein, which is present in every organ of the body that makes mucus, such as the lungs, liver, pancreas, and intestines, as well as sweat glands. The protein is also found in the heart cells and the immune system
• The mutations in the CFTR gene cause an abnormal functioning of the CFTR protein, leading to thick and sticky mucus that causes blockages in the lungs and digestive system. This also results in inflammation of the organs, such as the lungs and pancreas, leading to organ damage

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Cystic Fibrosis?

The signs and symptoms of Cystic Fibrosis may vary from one individual to another. It may be mild or severe and depend on the organ systems involved. These may include:

• General signs and symptoms: 
  • Clubbing of fingers and toes
  • Fever
  • Night sweats
  • Jaundice
  • Low body mass index (BMI)
  • Muscle and joint pain
  • Delayed growth/puberty
  • Salty skin
• Respiratory signs and symptoms: 
  • Wheezing
  • Persistent cough
  • Sinus infections
  • Stuffy nose
• Gastrointestinal signs and symptoms: 
  • Blockage of intestines in baby after birth
  • Foul-smelling stools

How is Cystic Fibrosis Diagnosed?

Cystic Fibrosis is usually diagnosable within the first month of life. The following can be used to diagnose the condition:

• Physical examination and evaluation of one’s family history
• Genetic tests to detect CFTR genes
• Prenatal diagnostic tests
• Sweat test for detecting high sweat chloride
• Immunoreactive trypsinogen (IRT) test
• Sputum test
• Chest X-ray
• CT scan
• Pulmonary function tests (PFTs)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the Possible Complications of Cystic Fibrosis?

Depending on the severity of Cystic Fibrosis, it may present a wide range of complications, which include:

• General complications: 
  • Diabetes
  • Fertility problems 
  • Heart failure
  • Kidney problems
  • Liver disease
  • Mental health problems
  • Pancreatitis 
  • Salt loss syndrome
  • Urinary incontinence
• Digestive system related complications: 
  • Cancers of the digestive tract
  • Malnutrition
• Respiratory system related complications: 
  • Collapsed lung (pneumothorax)
  • Allergic bronchopulmonary aspergillosis (ABPA)
  • Coughing up blood (hemoptysis)
  • Growths in the nose (nasal polyps)
  • Respiratory failure

How is Cystic Fibrosis Treated?

The treatment plan for Cystic Fibrosis depends on the severity and progression of the individual’s condition. Typically, the following treatment measures may be considered: 

• Airway clearance techniques to help loosen lung mucus
• Antibiotics to prevent or treat lung infections
• Anti-inflammatory medicines 
• Bronchodilators to relax the airways
• CFTR modulators (these may help improve the function of the faulty CFTR protein)
• Mucus thinners
• Feeding tubes
• Lung transplants
• Bowel surgery
• Oxygen therapy
• Liver transplant

With known mutations and knowledge of the defects in the CFTR gene products, directed therapy has the potential to be of benefit.

How can Cystic Fibrosis be Prevented?

Presently, Cystic Fibrosis is not a preventable condition since it is caused by genetic factors.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations is recommended.

What is the Prognosis of Cystic Fibrosis? (Outcomes/Resolutions)

• The prognosis of Cystic Fibrosis varies from one individual to another. However, in most individuals, the condition progresses such that disability due to lung disease is often observed
• The average life span of individuals with Cystic Fibrosis who live up to adulthood is about 44 years. In many, fatalities are noted from lung complications

Additional and Relevant Useful Information for Cystic Fibrosis:

• The Cystic Fibrosis gene mutation blood test is a test to identify genetic mutations in the CFTR gene

The following DoveMed article link provides more information on the CFTR gene lab test:

https://www.dovemed.com/common-procedures/procedures-laboratory/cystic-fibrosis-gene-mutation-blood-test/