Alpha-1 Antitrypsin Deficiency

What is alpha-1 antitrypsin deficiency (AAT deficiency)?

From: MedlinePlus, National Library of Medicine

Alpha-1 antitrypsin deficiency (AAT deficiency, or AATD) is an inherited condition that raises your risk for lung and liver disease. If you have this condition, your body doesn't make enough alpha-1 antitrypsin (AAT).

AAT is made by your liver. It helps protect your lungs from inflammation and irritating substances you might breathe in, such as smoke. If your liver doesn't make enough AAT, your lungs may be more easily damaged from smoking, pollution, or dust from the environment. This can lead to a serious lung condition called chronic obstructive pulmonary disease (COPD). AAT deficiency may also cause a liver disease called cirrhosis. This is more common in children who have AAT deficiency.

What causes alpha-1 antitrypsin deficiency (AAT deficiency)?

From: MedlinePlus, National Library of Medicine

AAT deficiency is a genetic disorder. That means it's caused by changes in your genes, which may also be called gene variants or mutations.

Your genes carry information that controls what you look like and how your body works. AAT deficiency is caused by changes in the SERPINA1 gene, which carries instructions for making the AAT protein. These gene changes are inherited from your parents, so AAT deficiency tends to run in families:

There are a few gene changes that cause AAT deficiency. These gene changes can:

• If you have two mutated copies of the gene, it means you have a condition called AAT deficiency. People with this disorder have a higher risk of getting lung disease or liver damage before the age of 45.
• If you have one mutated copy of the gene, you are a carrier of AAT deficiency. In these cases, this means you are at slightly higher risk of developing lung disease, especially if you have other risk factors, such as being a smoker. You could still pass the mutated gene on to your children.
• Decrease the amount of AAT protein your liver makes.
• Prevent your liver from making any AAT.
• Affect the shape of the AAT protein so that it can't move out of your liver to protect your lungs. Over time, AAT builds up in your liver and causes damage.

What are the symptoms of alpha-1 antitrypsin deficiency (AAT deficiency)?

From: MedlinePlus, National Library of Medicine

Some people who have AAT deficiency do not have any symptoms. For those who do, symptoms usually appear in people between 20 and 50 years old. These symptoms may include:

• Wheezing
• Shortness of breath, especially after exercise
• Chronic cough with phlegm (mucus)
• Repeated respiratory infections such as colds and the flu
• Chest pain
• Fatigue
• Faster-than-normal heartbeat when you stand up
• Vision problems
• Losing weight without trying

Some people who have AAT deficiency may have liver damage. Signs of liver damage include jaundice (a condition that causes your skin and eyes to turn yellow) and swelling in your legs.

Rarely, AAT deficiency can cause skin problems, such as painful lumps or patches.

How is alpha-1 antitrypsin deficiency (AAT deficiency) diagnosed?

From: MedlinePlus, National Library of Medicine

Your health care provider may test you for AAT deficiency if you have:

AAT deficiency in babies often affects the liver. Your baby may need AAT testing if he or she has signs of liver disease such as jaundice or abnormal liver enzyme tests.

A blood test can check the level of AAT protein in your blood. If the level is lower than normal, it is likely that you have AAT deficiency.

A genetic test is the most certain way to check for AAT deficiency and should be done to confirm the results of the blood test. There are two types of genetic tests:

If your lungs are affected, you may also have lung function tests to see how well your lungs are working.

• Symptoms of AAT deficiency
• A condition that could be related to AAT deficiency
• Relatives who have AAT deficiency
• Relatives who have a lung or liver disease that could be related to AAT deficiency
• A genotype test looks for the more common types of gene changes that can cause AAT deficiency.
• A phenotype test checks for changes in the AAT protein that change how it would normally work.

What are the treatments for alpha-1 antitrypsin deficiency (AAT deficiency)?

From: MedlinePlus, National Library of Medicine

There is no cure for AAT deficiency, but there are treatments to help with the symptoms and slow the lung damage it causes. Treatment options may include:

• Inhaled medicines to help you breathe better.
• Pulmonary rehabilitation.
• Oxygen therapy.
• Augmentation therapy, which is a lifelong treatment. It raises the levels of the AAT protein in your lungs, using ATT protein taken from the blood of donors. It helps slow down lung damage. It cannot prevent liver damage.
• Lung surgery or a lung transplant, if your lungs are severely damaged.
• Liver transplant, if your liver is severely damaged.

To help prevent or delay lung damage, it is important to quit smoking (if you smoke) and avoid secondhand smoke, dust, and air pollution. Ask your provider If you need to stop drinking alcohol.

Genetic causes described in the linked summary

From: MedlinePlus Genetics

Variants (also known as mutations) in the SERPINA1 gene cause alpha-1 antitrypsin deficiency. This gene provides instructions for making a protein called alpha-1 antitrypsin, which protects the body from a powerful enzyme called neutrophil elastase. Neutrophil elastase is released from white blood cells to fight infection, but it can attack normal tissues (especially the lungs) if not tightly controlled by alpha-1 antitrypsin.

Variants in the SERPINA1 gene can lead to a shortage (deficiency) of alpha-1 antitrypsin or an abnormal form of the protein that cannot control neutrophil elastase. Without enough functional alpha-1 antitrypsin, neutrophil elastase destroys alveoli and causes lung disease. Abnormal alpha-1 antitrypsin can also accumulate in the liver and damage this organ.

Environmental factors, such as exposure to tobacco smoke, chemicals, and dust, likely impact the severity of alpha-1 antitrypsin deficiency.

Inheritance described in the linked summary

From: MedlinePlus Genetics

This condition is inherited in an autosomal codominant pattern. Codominance means that two different versions of the gene may be active (expressed), and both versions contribute to the genetic trait.

The most common version (allele) of the SERPINA1 gene, called M, produces normal levels of alpha-1 antitrypsin. Most people in the general population have two copies of the M allele (MM) in each cell. Other versions of the SERPINA1 gene lead to reduced levels of alpha-1 antitrypsin. For example, the S allele produces moderately low levels of this protein, and the Z allele produces very little alpha-1 antitrypsin. Individuals with two copies of the Z allele (ZZ) in each cell have a high risk of developing lung disease (such as emphysema) and liver disease associated with alpha-1 antitrypsin deficiency. Those with the SZ combination have an increased risk of developing lung disease, particularly if they smoke.

Worldwide, it is estimated that 185 million people have one copy of the S or Z allele and one copy of the M allele in each cell (MS or MZ). Individuals with an MS (or SS) combination usually produce enough alpha-1 antitrypsin to protect the lungs. People with MZ alleles, however, have a slightly increased risk of impaired lung or liver function.

Which doctor should you see?

The suggested department for discussing Alpha-1 Antitrypsin Deficiency is Pulmonology, with a pulmonologist / chest physician as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• What is the likely explanation for the breathing symptoms?
• Would a breathing test or another investigation change management?
• If symptoms worsen, what written action plan should be followed?

Treatment discussions and follow-up

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.