What are some other names for Alpha-1 antitrypsin deficiency?
What is Alpha-1 antitrypsin?
What is Alpha-1 phenotyping?
Why do some ethnic groups have higher rates of Alpha-1 gene changes?

What are some other names for Alpha-1 antitrypsin deficiency?

Alpha-1 antitrypsin (pronounced "alpha-one anti-trip-sin") deficiency has many nicknames – some are simpler, some are just as complex.

• Alpha-1
• AAT deficiency
• Alpha-protease deficiency
• A1AD
• A1AT
• Protease inhibitor deficiency (PI)
• Pi phenotype (ZZ, Z-, --)

What is Alpha-1 antitrypsin?

Alpha-1 antitrypsin, or AAT, is a protein that circulates in the blood. AAT protects the tissues of the body from being damaged by natural enzymes in the body – especially those in white blood cells whose job is to protect the body from infections. When there is not enough AAT, these enzymes can start to break down healthy tissue cells in the body. AAT is most important in the lungs and the liver, where it is manufactured.

What is Alpha-1 phenotyping?

Phenotyping refers to the traditional way that Alpha-1 has been tested for over the years, even before genetic testing was available. Phenotyping looks at the total amount of AAT protein in the blood to see if the levels are missing or lower than normal. This test uses a process called isoelectric focusing and is considered the gold standard for diagnosing the condition.

Phenotyping helps doctors diagnose Alpha-1, but it does not identify what underlying genetic changes are responsible for the low levels of AAT. Therefore, it cannot provide information for family planning or for at-risk relatives who want to know if they have also inherited these Alpha-1 genetic changes.

Why do some ethnic groups have higher rates of Alpha-1 gene changes?

Genes are a family heirloom, and Alpha-1 is an inherited condition that gets passed down from generation to generation. Traditionally, Alpha-1 has been more common among certain ethnic or racial groups.

A simple way to think about this is that an ancestor, say in Northern Europe, thousands of years ago had a chance mutation in one of their Alpha-1 genes (Founder Effect Theory). An alternate theory is that the genetic change may have evolved as a protective mechanism (Beneficial Mutation Theory). This change genetic change then was passed down to more and more people within that region over the generations.

As this mutation passed down throughout generations, people who carried this genetic change had children with other people who also had the change. People who inherited two genetic changes (one from each parent) would then have an increased chance of developing Alpha-1-related disease.

Alpha-1 may actually be more common in non-European groups than traditionally thought, because the condition is often misdiagnosed and may be caused by genetic mutations other than S and Z, for which testing is currently available. This is an area that requires additional research.