What is Alpha-1?

The Basics The History The Genetic Path The Symptoms The Phenotypes The Treatments The Testing

What is alpha-1 antitrypsin deficiency (AATD)?

Alpha-1 antitrypsin deficiency (AATD) is an inherited condition that causes low levels of, or no, alpha-1 antitrypsin (AAT) in the blood. AATD occurs in approximately 1 in 2,500 individuals. This condition is found in all ethnic groups; however, it occurs most often in whites of European ancestry.

Alpha-1 antitrypsin (AAT) is a protein that is made in the liver. The liver releases this protein into the bloodstream. AAT protects the lungs so they can work normally. Without enough AAT, the lungs can be damaged, and this damage may make breathing difficult.

Everyone has two copies of the gene for AAT and receives one copy of the gene from each parent. Most people have two normal copies of the alpha-1 antitrypsin gene. Individuals with AATD have one normal copy and one damaged copy, or they have two damaged copies. Most individuals who have one normal gene can produce enough alpha-1 antitripsin to live healthy lives, especially if they do not smoke.

People who have two damaged copies of the gene are not able to produce enough alpha- 1 antitrypsin, which leads them to have more severe symptoms(1)

References:
1. What is Alpha-1 Antitrypsin Deficiency? National Genome Research Institute web site 2007 Feb <http://www.genome.gov/19518992>