University of Iowa Health Science Relations and
Jeffrey Wilson, MD
Professor of Internal Medicine
First Published: January 2003
Last Revised: February 2003
Peer Review Status: Internally Peer Reviewed

Lung physicians are spreading the word about a genetic disorder that can cause life-threatening lung or liver disease but is not widely recognized.

The genetic disorder is called Alpha-1 antitrypsin deficiency (AAT deficiency). An estimated 80,000 to 100,000 Americans are living with severe AAT deficiency, but less than 10 percent have been diagnosed.

Alpha-1 antitrypsin is a protein made largely in the liver that helps protect the lungs against damage from smoking and environmental respiratory irritants. In most patients with AAT deficiency, the protein cannot get out of the liver cells and into the bloodstream as it normally would.

"AAT deficiency is one of the most common serious hereditary disorders," said Jeffrey Wilson, MD, University of Iowa associate professor of internal medicine and a lung specialist at UI Hospitals and Clinics. "It can result in potentially fatal lung or liver disease in adults and liver disease among children."

AAT deficiency can lead to lung destruction (emphysema) and is often misdiagnosed as asthma or smoking-related chronic obstructive pulmonary disease. The disorder also can lead to liver failure during childhood and may cause progressive liver damage in adults. It is often undetected until it reaches a life-threatening stage.

"If AAT deficiency is detected early, we can intervene with smoking cessation, if appropriate, and we can replace the deficient protein with regular intravenous infusions. This may prevent some of the respiratory complications or at least slow the progress of the disorder," Wilson explained. However, one study showed it took seven years on average from the time respiratory symptoms first appear until the proper diagnosis is made, even though AAT deficiency can be detected by a simple blood test.

The most common symptoms of AAT deficiency include shortness of breath, wheezing, decreased tolerance for exercise, recurring respiratory infections and rapid deterioration of lung function with or without a history of significant smoking, chronic liver problems and elevated liver enzymes.

The World Health Organization (WHO) recommends that everyone with COPD and adults or adolescents with asthma be screened for AAT deficiency. Anyone with a family history of the disease should discuss being tested for AAT deficiency with a physician.