2.5.1 Cystic Fibrosis

• What type of disorder is Cystic Fibrosis?

  Genetic
• Cystic Fibrosis is caused by mutations in the CFTR
• The CFTR protein functions as a channel for potassium ions.

  False
• What is the most common mutation in the CFTR gene that causes CF?

  ΔF508
• Cystic Fibrosis follows an autosomal recessive inheritance pattern.
• Excessive mucus production is a common symptom of Cystic Fibrosis.
• Steps in the diagnosis of Cystic Fibrosis

  1️⃣ Newborn screening

  2️⃣ Sweat test

  3️⃣ Genetic testing
• Genetic counseling for Cystic Fibrosis helps carriers understand their risks
• Current research in Cystic Fibrosis focuses on improving treatment options.
• Which organs are affected by Cystic Fibrosis?

  Lungs, pancreas, digestive system
• Match the function of the CFTR protein with its description:

  Chloride ion channel ↔️ Regulates fluid balance

  Membrane protein ↔️ Embedded in cell membranes

  Fluid regulation ↔️ Ensures adequate mucus secretion
• Which mutation in the CFTR gene is caused by the deletion of a phenylalanine residue?

  ΔF508
• Cystic Fibrosis is inherited through autosomal recessive inheritance.
• If both parents are carriers of the CFTR gene, their offspring have a 25% chance of developing CF.
• What are the primary symptoms of Cystic Fibrosis?

  Excessive mucus, lung infections
• What type of disorder is Cystic Fibrosis?

  Genetic disorder
• Cystic Fibrosis is caused by mutations in the CFTR
• Cystic Fibrosis primarily affects the lungs, pancreas, and digestive system.
• What is a main symptom of Cystic Fibrosis related to mucus production?

  Excessive mucus production
• The CFTR protein regulates fluid flow across cell membranes
• What does the CFTR protein function as in cell membranes?

  Chloride ion channel
• The CFTR protein is essential for regulating fluid balance in the lungs and pancreas.
• The CFTR protein regulates the flow of fluids in organs like the lungs and pancreas
• Where is the CFTR protein located in the body?

  Cell membranes of organs
• Steps in the ΔF508 mutation process

  1️⃣ Phenylalanine is removed at position 508

  2️⃣ Protein misfolds

  3️⃣ Protein is degraded
• Cystic Fibrosis is inherited through autosomal recessive
• Individuals with Cystic Fibrosis must inherit one copy of the mutated gene from each parent.

  False
• What is the phenotype of an individual with the Cc genotype in CF inheritance?

  Carrier (no symptoms)
• In a Punnett square of two carrier parents, 25% of offspring inherit CC and are normal
• What is a key symptom of Cystic Fibrosis in the lungs?

  Excessive mucus production
• Match the symptom of Cystic Fibrosis with the affected organ/system:

  Excessive mucus production ↔️ Lungs

  Digestive issues ↔️ Pancreas
• Cystic Fibrosis symptoms include excessive mucus production in the lungs, which causes breathing difficulties
• Frequent lung infections in Cystic Fibrosis are caused by the accumulation of mucus in the airways.
• The symptoms of Cystic Fibrosis arise from a defective CFTR protein.
• Excessive mucus production is a symptom of Cystic Fibrosis.
• Digestive issues in Cystic Fibrosis are caused by pancreatic insufficiency.
• Order the diagnostic tests for Cystic Fibrosis from earliest to most confirmatory:

  1️⃣ Newborn Screening

  2️⃣ Sweat Chloride Test

  3️⃣ Genetic Testing
• What enzyme is analyzed in newborn screening for Cystic Fibrosis?

  Immunoreactive trypsinogen (IRT)
• The Sweat Chloride Test is considered the "gold standard" for CF diagnosis.
• A sweat chloride level of 60 mmol/L is considered positive for Cystic Fibrosis.