My son has a1 antitrypsin deficiency. can someone explain what this means?

A1AT -geneticdeficit: Alpha1 Antitrypsin is an enzyme produced in the liver.It's a protease inhibitor.Simply put, it works to protect the liver and lungs.Usually the lungs are most affected with complications of emphysema at a relatively early age (before 45 and without smoking history) - worse if there is a smoking history. Depending on whether there is partial or complete absence of the enzyme will dictate symptoms