Cystic Fibrosis: Pathophysiology, Genetics, Symptoms, Diagnosis and Treatments, Animation

Summary

Cystic fibrosis (CF) is a common inherited disorder that primarily affects the digestive, respiratory, and urogenital systems. It is caused by mutations in the CFTR gene, leading to thick mucus production and subsequent complications such as respiratory infections, digestive issues, and infertility. CF is inherited in an autosomal recessive manner, with the severity of the disease varying depending on the specific mutations. While there is no definitive cure, early diagnosis and treatment with medications and therapies can help manage symptoms and improve quality of life. New modulator drugs show promise in improving CFTR protein function.

Takeaways

• 😀 Cystic fibrosis (CF) is a common inherited disorder that shortens life expectancy, especially among individuals of Northern European origin.
• 😀 CF is caused by mutations in the CFTR gene, which encodes a chloride channel that regulates water and salt balance in secreted fluids like mucus and sweat.
• 😀 Mutations in the CFTR gene lead to thicker mucus production, which causes blockages and problems in various organs.
• 😀 CF is inherited in an autosomal recessive manner, meaning a child inherits one mutated gene from each parent, who are typically carriers without symptoms.
• 😀 Over 2000 CFTR mutations have been identified, with the most common being the deletion of phenylalanine at position 508, accounting for 70% of CF cases.
• 😀 The severity of CF varies depending on the mutations a patient inherits, with symptoms ranging from early life to late adulthood.
• 😀 CF primarily affects the digestive, respiratory, and urogenital organs, with respiratory insufficiency being the leading cause of mortality.
• 😀 Digestive symptoms include bile duct obstruction, poor fat absorption, pancreatitis, and insulin-dependent diabetes due to pancreatic damage.
• 😀 In the lungs, thick mucus can cause chronic infections, airway destruction, and symptoms like chronic cough, wheezing, and recurrent pneumonia.
• 😀 CF is included in newborn screening in many countries, involving tests like immunoreactive trypsinogen, DNA for common CFTR mutations, and sweat chloride testing for diagnosis.

Q & A

What is cystic fibrosis (CF)?

Cystic fibrosis (CF) is a common inherited disorder that leads to a shortened life expectancy, particularly among people of Northern European origin. It is caused by mutations in the CFTR gene, which encodes a protein involved in regulating chloride ions across cell membranes.

How does the CFTR protein work, and why is it important?

The CFTR protein functions as a chloride channel, allowing the movement of chloride ions across cell membranes. This action is crucial for regulating water and salt balance in secreted fluids, such as mucus and sweat, influencing the consistency of bodily fluids.

How do mutations in the CFTR gene affect the body?

Mutations in the CFTR gene lead to the production of thicker mucus in various organs, such as the lungs and pancreas. This thick mucus causes blockages, infections, and other complications in these organs.

How is cystic fibrosis inherited?

Cystic fibrosis is inherited in an autosomal recessive manner. This means a child must inherit one mutated CFTR gene from each parent to develop the disease. Parents are usually carriers with one mutated gene and one normal gene.

What is the most common mutation that causes cystic fibrosis?

The most common CFTR mutation is the deletion of the amino acid phenylalanine at position 508, which accounts for approximately 70% of all CF cases.

What factors influence the severity of cystic fibrosis?

The severity of cystic fibrosis depends on the specific mutations a patient has in their CFTR gene. Some mutations cause more severe forms of the disease, while others lead to milder symptoms.

What are some early symptoms of cystic fibrosis?

In infants, one of the earliest signs is meconium ileus, a bowel obstruction caused by thick, sticky stool. Other digestive symptoms may appear as early as childhood, including poor fat absorption, abdominal distension, and intestinal obstruction.

What are the main complications of cystic fibrosis in the digestive system?

In the digestive system, CF can cause obstruction of bile ducts and pancreatic ducts, leading to poor fat absorption, liver damage, pancreatitis, and diabetes due to damage to insulin-producing cells in the pancreas.

What is the leading cause of death in cystic fibrosis patients?

Respiratory insufficiency is the leading cause of death in cystic fibrosis patients, as chronic lung infections and airway damage significantly impact lung function.

How is cystic fibrosis diagnosed and managed?

Cystic fibrosis is often diagnosed through newborn screening, which includes an immunoreactive trypsinogen test, DNA test for CFTR mutations, and a sweat test. Management includes medications, therapies to clear mucus, and in severe cases, lung transplantation. Newer modulator drugs are also being developed to help correct CFTR protein dysfunction.