An inherited disorder causing low levels of alpha-1 antitrypsin (AAT), a protein protecting lungs from neutrophil elastase. Leads to early-onset emphysema (especially in smokers) and liver disease. Most common in European populations.

• 1Genetic testing
• 2Clinical evaluation
• 3Family history assessment
• 4Specialized laboratory tests
• 5Imaging studies
• 6Biopsy (if applicable)

Non-smokers with lung disease have near-normal life expectancy. Smokers lose 15+ years of life. Augmentation therapy slows emphysema progression by 30-50%. Lung transplant for end-stage lung disease offers 50-60% 5-year survival. Liver disease is less common but can cause cirrhosis and hepatocellular carcinoma; liver transplant curative. Screening of first-degree relatives identifies affected individuals before lung damage. Smoking cessation is the most important intervention.

• Genetic counseling
• Carrier screening
• Prenatal diagnosis
• Preimplantation genetic diagnosis
• Family planning