Cystic Fibrosis

Definition

Cystic fibrosis is a genetic disorder that primarily affects the respiratory and digestive systems. It is caused by a mutation in the CFTR gene, which is responsible for regulating the movement of salt and water in and out of cells. This disruption leads to the production of thick, sticky mucus that can clog the lungs and obstruct the pancreas, causing a range of health complications.

5 Must Know Facts For Your Next Test

1. Cystic fibrosis is one of the most common life-threatening genetic disorders, affecting approximately 70,000 individuals worldwide.
2. The most common mutation in the CFTR gene is the deletion of the amino acid phenylalanine at position 508 (F508del), which accounts for about 70% of cystic fibrosis cases.
3. Cystic fibrosis is typically diagnosed through newborn screening, genetic testing, or a sweat test that measures the concentration of chloride in the patient's sweat.
4. Individuals with cystic fibrosis often experience chronic respiratory infections, such as pneumonia and bronchitis, as well as digestive issues like malnutrition and pancreatic insufficiency.
5. While there is no cure for cystic fibrosis, advances in treatment have significantly improved the life expectancy and quality of life for individuals with the condition.

Review Questions

• Explain the role of the CFTR gene in the development of cystic fibrosis.
  • The CFTR gene is responsible for producing a protein that regulates the movement of salt and water in and out of cells. Mutations in this gene, particularly the common F508del mutation, lead to the production of thick, sticky mucus that can accumulate in the lungs, pancreas, and other organs. This mucus buildup is the primary cause of the respiratory and digestive complications associated with cystic fibrosis.
• Describe the pattern of inheritance for cystic fibrosis and how it relates to the likelihood of an individual developing the condition.
  • Cystic fibrosis is an autosomal recessive genetic disorder, meaning an individual must inherit two copies of the mutated CFTR gene, one from each parent, to develop the condition. If an individual inherits only one copy of the mutated gene, they will be a carrier but will not have cystic fibrosis. When two carriers have children, there is a 25% chance that each child will inherit two copies of the mutated gene and develop cystic fibrosis, a 50% chance that the child will be a carrier, and a 25% chance that the child will not have the condition.
• Analyze the impact of the CFTR gene mutation on the overall health and quality of life for individuals with cystic fibrosis, and discuss the current advancements in treatment that have improved their prognosis.
  • The CFTR gene mutation in cystic fibrosis leads to the production of thick, sticky mucus that can severely impair respiratory and digestive function. This can result in chronic respiratory infections, malnutrition, and other life-threatening complications. However, significant advancements in treatment, including the development of CFTR modulator therapies, have greatly improved the prognosis and quality of life for individuals with cystic fibrosis. These treatments target the underlying genetic defect, helping to restore CFTR protein function and reduce the buildup of mucus in the lungs and other organs. As a result, the life expectancy for individuals with cystic fibrosis has steadily increased, with many now living into their 40s and 50s, a marked improvement from the past when the condition was often fatal in childhood.

Related terms

CFTR Gene: The cystic fibrosis transmembrane conductance regulator (CFTR) gene is responsible for producing a protein that regulates the movement of salt and water in and out of cells. Mutations in this gene are the primary cause of cystic fibrosis.

Autosomal Recessive Inheritance: Cystic fibrosis is an autosomal recessive genetic disorder, meaning an individual must inherit two copies of the mutated CFTR gene, one from each parent, to develop the condition.

Mucus Buildup: In cystic fibrosis, the CFTR gene mutation leads to the production of thick, sticky mucus that can accumulate in the lungs, pancreas, and other organs, causing respiratory and digestive complications.