What Is Alpha-1 Antitrypsin Deficiency?

Alpha-1 antitrypsin deficiency — often called Alpha-1 or AATD — is an inherited condition in which the body does not produce enough of a protective protein called alpha-1 antitrypsin (AAT). This protein is made primarily in the liver and travels through the bloodstream to the lungs, where it shields delicate tissue from inflammation and enzyme damage.

When AAT levels are too low, or when the protein is misshapen and cannot function properly, the lungs gradually lose protection. Over time, this raises the risk of serious lung conditions, particularly emphysema (a form of chronic obstructive pulmonary disease, or COPD). In some cases, the abnormal protein also builds up inside liver cells, which can lead to liver disease.

Alpha-1 is caused by mutations in the SERPINA1 gene. A person inherits one copy of this gene from each parent, and the severity of the condition depends on which gene variants are inherited. It is considered one of the most common serious genetic disorders among people of Northern European descent, though it can affect individuals of many backgrounds.

~100,000

Americans estimated to have Alpha-1

The Alpha-1 Foundation estimates that roughly 100,000 Americans are affected, with many more carrying a single deficient gene variant without knowing it.

7+ years

Average diagnostic delay

Studies published in respiratory medicine journals have documented average delays of seven or more years between symptom onset and Alpha-1 diagnosis.

1 in 2,500

Prevalence in populations of European descent

Alpha-1 is estimated to affect approximately 1 in 2,500 individuals of Northern European ancestry, making it one of the more common serious inherited conditions.

Why It Often Goes Undiagnosed for Decades

One of the most clinically significant challenges with Alpha-1 is how long it can remain hidden. Research has found that on average, individuals wait many years — sometimes more than a decade — between the onset of symptoms and receiving a correct diagnosis. This delay occurs for several reasons.

The early symptoms of Alpha-1-related lung disease closely resemble those of common conditions like asthma or smoking-related COPD. Persistent breathlessness, wheezing, or a recurring cough can be attributed to other causes before anyone considers a genetic origin. Liver involvement may be entirely silent until disease is more advanced.

Additionally, because Alpha-1 is inherited, family members who might share the genetic risk are rarely flagged unless a relative has already been diagnosed. Older adults who developed breathing difficulties before genetic testing was widely available may never have been offered this specific test.

Misdiagnosis Is Common — and Consequential

Alpha-1-related lung disease is frequently misdiagnosed as ordinary asthma or smoking-related COPD. This matters because the management approach differs, and delays in identifying Alpha-1 can mean years without appropriate monitoring or intervention. If you or a family member has been diagnosed with COPD, emphysema, or unexplained liver disease, it is reasonable to ask a clinician whether Alpha-1 testing has been performed.

How Alpha-1 Affects the Lungs and Liver

Lung effects: Without adequate AAT protection, an enzyme called neutrophil elastase — normally useful for fighting infection — begins to break down healthy lung tissue. This leads to emphysema, characterized by the gradual destruction of the tiny air sacs (alveoli) that allow oxygen to enter the bloodstream. Symptoms typically include shortness of breath with exertion, chronic cough, and increased susceptibility to respiratory infections. Smoking dramatically accelerates this damage; individuals with Alpha-1 who smoke face a significantly earlier and more severe disease course.

Those concerned about overlapping lung risks may also find it useful to read about lung cancer in older adults, since respiratory symptoms warrant thorough evaluation.

Liver effects: When the AAT protein is produced in an abnormal form, it can accumulate within liver cells rather than being released into the bloodstream. This buildup can cause inflammation and, over time, scarring (cirrhosis) or, less commonly, liver cancer. Not everyone with Alpha-1 develops liver disease, and the severity varies considerably between individuals.

Ask your doctor specifically about Alpha-1 testing if you have been diagnosed with COPD or emphysema but have never smoked heavily — this combination is a strong clinical signal worth investigating.

Guidelines from the Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommend Alpha-1 testing for all individuals diagnosed with COPD, regardless of smoking history, because the genetic cause is frequently overlooked.

Keep a written record of your AAT protein level and genetic variant to share with every clinician you see — including those treating unrelated conditions — because some medications and procedures have implications for lung and liver health.

Coordinated care depends on all members of a healthcare team being aware of an underlying genetic condition that affects multiple organ systems.

Getting Tested and Understanding Your Results

Diagnosis begins with a straightforward blood test that measures the level of AAT protein in the bloodstream. If levels are below normal, genetic testing can identify which specific variants of the SERPINA1 gene are present. The most clinically significant variants are labeled by letters; the most common severe combination involves two copies of what is called the Z variant.

Results are typically interpreted by a pulmonologist (lung specialist), hepatologist (liver specialist), or a clinician with expertise in genetic conditions. Understanding your specific variant matters because it shapes both your risk level and the monitoring approach your care team will recommend.

Not All Carriers Develop Serious Disease

Having one deficient gene variant (being a 'carrier') rather than two typically results in AAT levels low enough to be measured but often not low enough to cause significant lung or liver disease on their own. However, carriers who smoke or are exposed to significant lung irritants may still face elevated risk. Understanding your specific genetic result — not just whether Alpha-1 is 'present' — is important for accurate risk assessment.

Lung function tests, such as spirometry, are often conducted alongside blood tests to assess whether, and to what degree, breathing capacity has already been affected. Liver function blood tests and imaging may be ordered if liver involvement is suspected.

Managing Daily Life with Alpha-1

There is currently no cure for Alpha-1, but several well-established strategies can help slow its progression and maintain quality of life for older adults.

  • Avoid smoking entirely. This is the single most important modifiable factor for lung health in Alpha-1. Even long-term smokers benefit meaningfully from stopping.
  • Minimize exposure to lung irritants. Dust, chemical fumes, and air pollution accelerate lung damage. Good ventilation and protective equipment in relevant environments matter.
  • Stay current on vaccinations. Respiratory infections are particularly harmful. Influenza, pneumococcal, and COVID-19 vaccines are generally recommended; discuss the appropriate schedule with a healthcare provider.
  • Engage in appropriate physical activity. Maintaining aerobic capacity supports lung and overall health. See our resource on aerobic and resistance exercise for older adults for a balanced overview.
  • Augmentation therapy: For those with significant lung disease and low AAT levels, intravenous infusions of AAT protein derived from human plasma — called augmentation therapy — are an established treatment. Whether this therapy is appropriate depends on individual clinical factors and should be discussed with a specialist.

Alcohol should be consumed with caution or avoided if liver disease is present. A registered dietitian familiar with liver conditions can offer personalized guidance.

Build a Care Team That Covers Both Organs

Because Alpha-1 can affect both the lungs and the liver, coordinating care between a pulmonologist and a hepatologist — along with your primary care provider — leads to more thorough monitoring. Some academic medical centers have dedicated Alpha-1 clinics where multidisciplinary teams work together. Ask your primary care provider whether a referral to such a center is appropriate for your situation.

Family History and Genetic Implications

Because Alpha-1 follows an autosomal codominant inheritance pattern, each biological child of an affected parent has a meaningful chance of inheriting one or two copies of a deficient gene variant. Siblings of a diagnosed individual are also at increased risk. This makes family communication an important part of living with Alpha-1 — not to cause alarm, but to give relatives the opportunity to be tested and, if needed, begin monitoring early.

Genetic counseling can be valuable here. A genetic counselor can explain inheritance patterns clearly, help family members understand their own risk, and guide conversations that can feel emotionally complex. For older adults who may have adult children or grandchildren, this discussion is worth having with the support of a knowledgeable clinician.

If you are managing multiple aspects of aging-related health alongside Alpha-1, broader cardiovascular and organ health also deserve attention. Our overview of cardiovascular health in older men addresses related considerations for long-term wellbeing.

“Alpha-1 antitrypsin deficiency is vastly underdiagnosed. The majority of people who have it have never been tested, and that means they are missing the opportunity to take steps that could genuinely slow the disease.”

— Robert Sandhaus, Pulmonologist and Alpha-1 clinical researcher, National Jewish Health

This article is for general informational purposes only and does not constitute medical advice. If you have concerns about Alpha-1 antitrypsin deficiency or related symptoms, please consult a qualified healthcare professional for evaluation and guidance specific to your situation.