Alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder that causes lung and liver diseases. The prevalence is 25 in 100,000 (0.025%) in general population. Asia has relatively less incidence of AATD compared to Europe or North American population.

Affected people have little or no alpha-1 antitrypsin (AAT) protein in their blood. This condition is a result of SERPINA1 gene mutation, resulting in AAT deficiency. Hence the control of enzyme elastase (a biocatalyst that breaks down protein elastin) by AAT is compromised. Uncontrolled neutriphil elastase activity and resulting increased elastin degradation destroys the elastic architecture of alveoli (gas exchange pockets in lungs) and can lead to emphysema which could be accelerated by smoking. The severity of asthma increases in persons with AATD. Less commonly AATD cause liver disease and rarely skin disease, penniculitis.

AATD cases are sometimes misdiagnosed as a form of Chronic Obstructive Pulmonary Disease. AATD cannot be cured but can be treated. Treatment involves replacement therapy in which AAT is injected in the affected person once a week, but severe cases may require a lung transplant.

Contributor: Duraiswamy Navaneetham PhD.

Temple University School of Medicine

Philadelphia, PA, USA

July 2009