Cystic Fibrosis

Question 1

Definition of cystic fibrosis

Answer 1

Inherited autosomal recessive disease caused by gene mutation - a single gene defect on chromosome 7

Question 2

Pathophysiology of cystic fibrosis

Answer 2

• Chromosome 7 encodes cystic fibrosis transmembrane regulation (CFTR) protein
• CFTR protein = CF membrane conductance regulator
• Involved in Cl ion and water (regulates h2o in/outside cell) transport across membranes
• Therefore defect changes structure of CFTR protein impairing Cl ion transport causing abnormal Na + h2o levels in cells
• affects any organ relying on CFTR protein for ion transport
• ducts obstructed with sticky mucus (builds up outside cell, breeding ground for infection) causing inflammation + replacement of damaged cells with connective tissue (scarring)

Other simaile proteins can cause CF but this is most common
> 1500 mutations of CFTR gene, so different variations of CFTR protein making treatment difficult

Question 4

Consequences of defect in CFTR protein

Answer 4

Respiratory disease -