ICD-9-CM 273.4 is a billable medical code that can be used to indicate a diagnosis on a reimbursement claim, however, 273.4 should only be used for claims with a date of service on or before September 30, 2015. For claims with a date of service on or after October 1, 2015, use an equivalent ICD-10-CM code (or codes).
A genetic disorder characterized by decreased alpha-1 antitrypsin activity in the lungs and blood and deposition of alpha-1 antitrypsin protein in the hepatocytes. These abnormalities result from defective production of alpha-1 antitrypsin and lead to the development of emphysema, cirrhosis, and liver failure
Alpha-1 antitrypsin deficiency is an inherited disorder that can cause lung disease in adults and liver disease in adults and children. Alpha-1 antitrypsin (aat) is a protein that protects the lungs. The liver usually makes the protein, and releases it into the bloodstream. Because of a gene problem, some people have little or none of it. Not having enough aat puts you at risk of emphysema or liver problems. If you smoke, you increase your risk. Children with aat deficiency can develop liver problems that last their whole lives. Aat deficiency can be treated but not cured. One treatment involves adding to or replacing the missing protein. A lung transplant may be an option if you are seriously ill. Staying away from cigarette smoke is crucial.a blood test can tell if you have the deficiency. If you have it, your family members should also take the blood test
Autosomal recessive trait leading to destruction of lung tissue by neutrophil elastase and eventual emphysema; second only to cystic fibrosis as most common lethal genetic disorder among caucasians of northern european ancestry
Deficiency of the protease inhibitor alpha 1-antitrypsin that manifests primarily as pulmonary emphysema and liver cirrhosis
2015 ICD-9-CM Diagnosis Code 273.4 
AAT (alpha-1 antitrypsin) 273.4
serum
