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How Do Genetics Play a Role in Alpha-1 Protein Levels?

Here's what you'll learn on this page:

Your genotype determines how much alpha-1 protein your body makes—common alleles range from M (normal) to Z and Null (undetectable amount), with ZZ producing severely deficient levels

What is a normal alpha-1 antitrypsin level? Normal alpha-1 protein levels are 20 μM or higher

Lower levels may mean higher risk, and lung damage can begin before symptoms appear

Protection varies on a spectrum based on your individual protein levels, environmental exposures, and lung health history

Alpha-1 affects people differently, and your genotype determines how much alpha-1 protein your body produces, and how much protection your lungs have.

What does your genotype mean for you?

Your Alpha-1 genotype is made up of 2 alleles—1 inherited from each parent. Some of the different alleles include:

M

Makes normal amount of working alpha-1 protein

S

Makes some alpha-1 protein, but less than normal

Z

Makes very little working alpha-1 protein

Null

Makes no working alpha-1 protein

Typical alpha-1 protein level ranges by genotype

Normal alpha-1 protein levels are 20-53 μM. In addition to lifestyle and environmental factors, lower alpha-1 protein levels can lead to greater risks.

Table showing alpha-1 antitrypsin levels by genotype, with higher levels in MM and much lower levels in ZZ, and normal levels defined as 20 micromolar or higher

Understanding your level of protection

Your level of protection depends on more than just your genotype—it can also vary from person to person.

Diagram showing four common alpha-1 antitrypsin genotypes (MM, MZ, SZ, ZZ), with decreasing protection and increasing risk of lung and liver disease

Why do your alpha-1 protein levels matter?

Alpha-1 protein levels and the protection they provide can differ from person-to-person, even those with the same genotype, based on different lifestyle factors.


You may feel fine today, but your alpha-1 protein levels could still be lower than what your lungs need to stay protected. When levels fall below normal, your lungs may be exposed to ongoing damage, even before symptoms appear.

Illustration of the alpha-1 antitrypsin protein

Your protection is shaped by more than your genotype.

Several factors influence your individual risk, including:

Icon of a bar chart

Your alpha-1 protein levels

Icon of trees representing environmental factors

Environmental exposures such as smoke, dust, air pollution, and other lifestyle factors

Icon of lungs

Your overall lung health and history of exacerbations

Explore ways to help reduce your Alpha-1 risk

MAT-US-2604701-v1.0-05/20026. Last updated May 2026.
How Your Inherited Genotype Affects Alpha-1 Risk