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
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
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.