Alpha-1 is a recessive condition. This mean that, in order to develop complications from Alpha-1, people typically must inherit two altered copies of the AAT gene – one from their mother and one from their father.

People who inherit just one altered copy of the AAT gene are called carriers. Carriers typically do not develop complications related to Alpha-1. Some studies have shown that some carriers – especially smokers – can develop lung damage.

Carriers can also pass on the AAT change to their children. If they have children with another Alpha-1 carrier, their children are at risk for inheriting Alpha-1.