Genetic Disorders
Cystic Fibrosis
낭성섬유증
Multi-organ disease of thick secretions due to CFTR mutation
- How common
- 1 in 2,500 (Caucasian; rare in Asians)
- Typical age
- Infant/childhood onset
What is it?
CFTR (7q31) mutation → defective chloride channel → thick mucus → blocks lung, pancreas, gut.
Commonly affected: Lungs, pancreas, gut, liver, vas deferens, sinuses
How it develops
- CFTR mutation (AR)ΔF508 most common (70%)
- Cl⁻/HCO₃⁻ defectMucus dehydrated → thickened
- Duct obstruction + infectionBronchi, pancreas, vas deferens blocked; P. aeruginosa
- Multi-organ failureRespiratory failure + exocrine pancreatic insufficiency
Symptoms
- Chronic cough + sputumThick mucus, repeat infections
- Pancreatic insufficiencySteatorrhea, malabsorption, FTT
- Male infertility (CBAVD)Congenital bilateral absence of vas deferens
- Salty sweat"Salty kiss" in infants
- Clubbing + cyanosisChronic hypoxia
How it is examined
- Sweat chloride test≥60 mEq/L diagnostic
- Newborn screenIRT (immunoreactive trypsinogen)
- CFTR genotypingConfirm 2 CFTR mutations (e.g., ΔF508)
Imaging
CXR: bronchiectasis, hyperinflation, mucus plugs.
- Bronchiectasis
- Mucus plugging
- Hyperinflation
HRCT chest to assess bronchiectasis.
- Cystic bronchiectasis
- Mucus impaction
Non-surgical care
- Airway clearancePEP device, chest PT, hypertonic saline
- Inhaled dornase alfaReduces mucus viscosity
- Pancreatic enzymesPancrelipase with meals
- CFTR modulators (ivacaftor)Targeted for ΔF508 and others
- AntibioticsAcute exacerbation + chronic inhaled (tobramycin)
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
End-stage lung disease, bronchiectasis complications
Procedures that may be discussed
- Bilateral lung transplant
- Liver transplant (biliary cirrhosis)
- Sinus surgery
Outlook
Median survival now >50 years in CFTR modulator era.