Alpha-1 Antitrypsin Deficiency (Alpha-1) is a genetic condition that is passed from parents to children through genes.

What causes Alpha-1?

Alpha-1 is passed down from parents to children through genes. People with Alpha-1 have mutations in a gene called SERPINA1. 

The SERPINA1 gene provides instructions for making a protein called alpha-1 antitrypsin (AAT), which protects the body from damage by its immune cells. 

If you have Alpha-1, you inherited two copies of the abnormal SERPINA1 gene–one from each parent. 

More About Alpha-1 Mutations

More than 150 different mutations in the SERPINA1 gene have been identified, but only a few can cause serious lung, liver or skin disorders. The most common of these are called S and Z. 

  • ZZ: People who inherit two ZZ mutations—one from each parent—have extremely low levels of AAT in the blood, which increases their risk of developing lung disease. 
  • SZ: People who inherit an S mutation and a Z mutation—one from each parent—have very low levels of AAT in the blood, which increases their risk of developing lung disease. However, people with SZ mutations are less likely to develop lung disease than people with ZZ mutations. 

Many people with Alpha-1, including those with SZ or ZZ mutations, have no symptoms of the condition. 

Watch this video to learn more about the genetics of Alpha-1

What is an Alpha-1 carrier?

People who inherit one defective copy of the SERPINA1 gene and one normal copy of the SERPINA1 gene are known as Alpha-1 carriers. An estimated 19 million people in the United States are Alpha-1 carriers. 

Alpha-1 carriers do not have Alpha-1, but can pass the abnormal SERPINA1 gene to their children. If both parents are Alpha-1 carriers, their children have a 1 in 4 chance of inheriting Alpha-1 and a 1 in 2 chance of being an Alpha-1 carrier. 

Family Planning

If you have Alpha-1 or are an Alpha-1 carrier and are planning to have children, you may want to talk to an Alpha-1 genetic counselor. A genetic counselor can answer questions about the risk of your future child(ren) inheriting Alpha-1 and explain the choices that are available.

Call 1-855-476-1227 to schedule an appointment with a genetic counselor through the Alpha-1 Foundation

Can Alpha-1 be prevented?

Because Alpha-1 is inherited, there is no way to prevent it.  However, if you have Alpha-1, there are steps you can take to reduce your risk of developing lung disease or liver disease. Avoiding behaviors that harm the lung and liver, such as smoking or drinking alcohol, is the best way to stop or slow Alpha-1 from causing damage to the lungs or liver.