Alpha-1 antitrypsin (AAT) deficiency occurs in all ethnic groups. However, the condition occurs most often in White people of European descent.
AAT deficiency is an inherited condition. "Inherited" means the condition is passed from parents to children through genes.
If you have bloodline relatives with known AAT deficiency, you're at increased risk for the condition. Even so, it doesn't mean that you'll develop one of the diseases related to the condition.
Some risk factors make it more likely that you'll develop lung disease if you have AAT deficiency. Smoking is the leading risk factor for serious lung disease if you have AAT deficiency. Your risk for lung disease also may go up if you're exposed to dust, fumes, or other toxic substances.