Cystic Fibrosis Gene
Located on chromosome 7
Codes for CFTR (cystic fibrosis transmembrane conductance regulator protein)
DeltaF508 is the most common
Effect of Mutated CFTR
Defective chloride transport and enhanced sodium absorption.
The net effect is less water going to the mucociliary layer, which causes thickening, impaired mucociliary clearance, imflammation, and infection.
Chloride Sweat Test
For diagnosis of CF
Sweat chloride is high in CF (>60 mmol/L)
Normal is <30
Which Systems Does CF Affect?
Any system that relies on mucus.
Can present with chronic sinusitis, nasal polyps, repreated LRTI, abnormal sweat secretions, liver disease, pancreatic insufficiency, intestinal obstruction sydrome, finger clubbing, steatorrhea, osteoporosis, intertility, and arthropathy.
Common Presenting Symptoms
Acute or persistent respiratory symptoms
Nasal polyps/sinus disease
Failure to thrive/malnutrition
Newborn screening (in 2016)
Treatment Principles in CF
Enhance mucus clearance
Most Common Pathogens in CF
Fertility in CF
Males are often infertile because of a closed vas deferens.
Females have markedly reduced fertility, but may still become pregnant.
Massive Hemoptysis in CF
Can occur due to erosion into bronchial circulation.
Treatment is ABCs and bronchiol artery embolization.
A drug approved for patients with a certain mutation in CF which accounts for about 5% of patients with CF.
Demonstrates an improvement in CF by addressing the underlying cause.
Costs $300,000 USD per year