Alpha-1 Antitrypsin (AAT) Deficiency: Symptoms, Causes, Diagnosis, Treatment

Medically Reviewed by Dr. K on 13 May 2022.

What Is AAT Deficiency?

Alpha-1 antitrypsin deficiency, also known as  AAT deficiency,  is a genetic disease passed down from parents to their children. The disease is caused by the inability to produce enough protein called alpha-1 antitrypsin, AAT. AAT is necessary to protect your lungs. Without AAT, infections and irritants, like tobacco smoke, damages your lungs, leading to serious liver and lung diseases. Symptoms include difficulty breathing and yellowing of skin, known as jaundice. There is no known cure, however new treatments are able to manage liver and lung complications.

Symptoms from AAT deficiency may not be apparent or obvious until you reach your 20s or 30s. At which point, you may start noticing symptoms like shortness of breath, difficulty breathing and even wheezing.

AAT deficiency can cause chronic obstructive pulmonary obstructive disease (COPD) for certain people. COPD causes symptoms of emphysema, a disease that makes it difficult for lungs to expel air. Other symptoms of COPD including coughing up mucus, wheezing, difficulty breathing and shortness of breath, as well as chest tightness. Chronic bronchitis is another lung complication AAT deficiency can lead to that causes airway irritation, causing you to cough and cause further problems with your breathing.

A common medication that will help you with your breathing is an inhaler. This will need to be carried around with you everywhere you go.

Not every case of AAT deficiency leads to severe disease. When the disease is managed well, most people are able to carry on their normal lives to include work, exercise and their regular day to day activities and hobbies.

Support from friends and family, as well as your doctor, can help you a lot. Your doctor can also refer you to support groups where they are people living with the same condition for you to connect with.

Symptoms of AAT Deficiency

Symptoms of the disease may not be obvious until you are an adult, generally between 20 to 40 years old. Symptoms include feeling very short of breath, especially when you are exercising. Some people even complain of wheezing, which sounds like your lungs are producing a whistling sound. Some people will also notice getting frequent lung infections.

Some red flag warning symptoms include:

  • Feeling very fatigued or tired
  • Palpitations or rapid heart beating
  • Unexplained weight loss

AAT deficiency that affects your liver will produce symptoms like:

  • Yellowing of eyes and skin – jaundice
  • Swelling of your abdomen or legs
  • Coughing up blood

A newborn infant with AAT deficiency will have symptoms like::

  • Yellowing of eyes and skin – jaundice
  • Dark yellow urine
  • Difficulty gaining weight
  • Enlarged liver
  • Excessive bleeding from the infant’s umbilical stump or nose

Panniculitis is a rare skin disease that people with AAT deficiency also get. Panniculitis causes hardening of the skin with widespread patches and painful lumps.

Causes of AAT Deficiency

Alpha-1 antitrypsin deficiency is a genetic disease that is passed along in families. Getting the disease means that it was passed down to you through the generations from either your biological father or mother. Some people have the genes however never have any symptoms of the disease. Other people have the genes but only develop mild symptoms of the disease.

Defective genes that are passed down from your parents are the cause of lower levels of the AAT protein within your blood. This can build up in your liver leading to liver diseases. The deficiency of AAT protein causes lung disease.

Investigations to diagnose AAT Deficiency

Your doctor will ask you questions like:

  • Do you have difficulty breathing?
  • Do you have frequent colds or chest infections?
  • Have you lost any weight without trying to recently?
  • Have you noticed your skin or eyes having a new yellow colour to them?

Your doctor will also examine your chest for breathing and extra noises like wheezing, and look for other signs indicating that your lungs are not working well.

A blood test is also needed to confirm your diagnosis. The blood test will check for these defective genes for AAT deficiency, and also how much of the proteins you have in your blood.

Your doctor will also need to assess how much damage has been done to your lungs and your liver. A chest X-ray will be needed to look for signs of emphysema. Another test will look for levels of oxygen in your arteries, indicating how well or poorly your lungs are working. Another test, spirometry, will require you to breathe into a tube to assess how much air efficiently transports into your lungs.

Another set of blood test will assess for liver damage. A liver biopsy will also be required. This involves a long thin needle to remove some cells to be examined for signs of liver damage.

Treatments for AAT Deficiency

There is no known cure for AAT deficiency, however if levels of AAT protein in your blood is raised enough, this will form some further protection from lung damage. This is referred to as augmentation therapy or replacement therapy, which is also used in the treatment of emphysema.

Augmentation therapy provides the patient with healthy AAT protein donated from a healthy human donor with sufficient levels of AAT protein via an IV line. This treatment is required to be carried out once a week for adequate levels to be reached. The treatment can also be carried out at home for more convenience.

Lifelong treatment for AAT deficiency is required to slow or prevent further damage to your lungs and liver. Whatever damage has already been done will not be reversed with treatment.

Inhalers are required for some patients with more severe breathing difficulties and lung damage. These are known as bronchodilators, medications that open your airways to ease your breathing.

Patients with low levels of oxygen in their blood will require oxygen via a nasal cannula or mask. These patients will also need referral for pulmonary rehabilitation to learn how to breathe more efficiently.

Looking After Yourself

People living with AAT deficiency must learn to adopt new habits to stay healthy. Patients are advised to stop smoking. An annual flu shot and pneumonia vaccine is also needed to ensure lung protection. Your doctor can also advise you on safe exercise you can practice to strengthen your lungs.

Healthy balanced diet will ensure your liver is in good shape. Good hand hygiene is also important to prevent infections. Limit alcohol consumption to protect your liver from injury. Areas with a lot of dust and smoke should be avoided.

Infants born with AAT deficiency will need a special baby milk formula fortified with additional vitamins. Regular doctors appointments is very important to ensure the child is growing adequately and that their lungs and liver are in healthy condition.

Support from loved ones, friends and family, will help you a lot. Your doctor can also refer you to support groups where they are people living with the same condition for you to connect with. These support groups help tremendously so you can connect with people who understand the disease you have and what you are going through.


What to Expect

This disease affects everyone with the condition differently ranging from none, mild to severe problems. Young children and infants diagnosed with this disease are more likely to develop more liver damage than lung damage. But despite this, only around 10% of young children develop severe liver disease. Young children may also develop asthma.

Patients will be sensitive to allergens like dust and smoke. The common colds may lead to breathing difficulties. 30% to 40% of patients will develop liver conditions at some stage.

Diagnosing your condition is the first step towards building a network of support, treatments and health living habits to ensure your disease is well managed.


Seek Support

Further information on a list of doctors, support groups, genetic counselling and more information can be found on Alpha-1 Foundation website.


Referenced on 2.3.2021:

  1. Alpha-1 Foundation: “What is Alpha-1?"
  2. American Lung Association: “Alpha-1 Antitrypsin Deficiency."
  3. American Thoracic Society: “Patient Information Series: What is Alpha-1 Antitrypsin Deficiency?"
  4. Children's Liver Disease Foundation: “Alpha-1 Antitrypsin Deficiency."
  5. Cleveland Clinic: “Alpha-1 Antitrypsin Deficiency Center."
  6. National Heart, Lung, and Blood Institute: “What to Expect During Lung Function Tests," “What is COPD?"
  7. National Human Genome Research Institute: “Learning About Alpha-1 Antitrypsin Deficiency."
  8. National Jewish Health: “Alpha-1 Antitrypsin Deficiency: Inherited Liver Disease."

Previous Post

Agoraphobia: Causes, Risk Factors, Symptoms, Treatment, Recovery

Next Post

How To Prevent Altitude Headache

Related Posts