Cystic Fibrosis Flashcards
What is cystic fibrosis?
Autosomal recessive condition
Mutation in CFTR gene on chromosome 7
Results in defective chloride channels
What is the result of defective chloride channels?
Defective chloride secretion and increased sodium absorption across airway epithelium
Changes in composition of airway surface liquid
CF Lungs are predisposed to?
Chronic infections and bronchiectasis
What are neonatal features?
Failure to thrive
Meconium ileus
Rectal prolapse
What is meconium ileum?
bowel obstruction that occurs when the meconium in a child’s intestine is even thicker and stickier than normal meconium
What is rectal prolapse?
mucosal or full-thickness layer of rectal tissue protrudes through the anal orifice
How many people carry the gene for CF?
1 in 24/25
Because CFTR is an ATP-activated channel feedback loop from other chloride channels and a negative effect on sodium entry causes?
Dryness in the lumen
What are children & young adult features of CF?
Cough Wheeze Recurrent infections Bronchiectasis Pneumothorax Haemoptysis Respiratory failure Cor Pulmonale
CF causes pancreatic insufficiency leading to?
Diabetes mellitus Steatorrhea Distal intestinal obstruction syndrome (equivalent of meconium ileum) Gallstones Cirrhosis
What are other features of CF in adults (other than respiratory and GI)?
Male infertility Osteoporosis Arthritis Vasculitis Nasal polyps Sinusitis hypertrophic pulmonary osteoarthropathy
What are clinical signs of CF?
Cyanosis
Finger clubbing
Bilateral coarse crackles
How can CF be diagnosed?
Sweat test Genetic screening Faecal elastase FBC, U&E, LFT Vitamin levels Glucose tolerance test Sputum culture CXR USS
What is a positive result for a sweat test?
Sodium and chloride >60 mmol/L (chloride usually > sodium)
What does faecal elastase test for?
Exocrine pancreatic dysfunction
