Cystic Fibrosis

Question 1

What sort of genetic disorder is CF?

Answer 1

Autosomal recessive disorder.

Question 2

What is the pathophysiology of CF?

Answer 2

There is a defect in the CF transmembrane conductance regulator gene (CFTR) which codes a cAMP-regulated chloride channels.

80% of cases are due to delta F508 on the long arm of chromosome 7.

And thus there is increased saltiness/viscosity of secretions (lungs, pancreas, skin)

Question 3

What are some organisms which commonly colonise CF patients?

Answer 3

• Staphylococcus aureus
• Pseudomonas aeruginosa
• Burkholderia cepacia
• Aspergillus

Question 4

What are some main features of CF?

Answer 4

• Neonatal period (20%): meconium ileus
  
  • Prolonged jaundice (rare)
• Recurrent chest infections (40%)
• Malabsorption (30%): Steatorrhoea, failure to thrive.
• Other features (10%): Liver disease

Question 5

What are some other features of CF?

Answer 5

• Short stature
• Diabetes Mellitus
• Delayed puberty
• Rectal prolapse (due to bulky stools)
• Nasal polyps
• Male infertility & female subfertility.

Question 6

Describe the management process of CF?

Answer 6

1. MDT approach
2. Regular (>BD) chest PT and postural drainage. (Patients taught to do this)
3. High calorie diet
4. Vitamin supplementation
5. Pancreatic enzyme supplements taken with every meal.
6. Heart and lung transplant.

Question 7

What is the carrier rate of CF?

Answer 7

1 in 25

Question 8

Per birth, what is the rate of CF?

Answer 8

1 in 2,500