Alpha-1 Antitrypsin Deficiency
Alpha-1 antitrypsin deficiency (AATD) is an inherited genetic condition that significantly increases the risk of developing serious lung and liver diseases.
Overview
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 does not produce enough alpha-1 antitrypsin (AAT).
AAT is produced by your liver and helps protect your lungs from inflammation and irritating substances, such as smoke. If your liver does not produce enough AAT, your lungs may be more easily damaged by smoking, pollution, or environmental dust. This can lead to a serious lung condition called chronic obstructive pulmonary disease (COPD). AAT deficiency may also cause a liver disease called cirrhosis, which is more common in children with the condition.
Causes & Risk Factors
AAT deficiency is a genetic disorder caused by changes, or mutations, in the SERPINA1 gene, which carries instructions for making the AAT protein. Because these changes are inherited, the condition tends to run in families:
- Two mutated copies: You have AAT deficiency, which carries a higher risk of lung disease or liver damage before age 45.
- One mutated copy: You are a carrier. You are at a slightly higher risk of developing lung disease, particularly if you are a smoker, and you can pass the gene to your children.
Gene changes associated with AAT deficiency can decrease AAT production, prevent it entirely, or alter the protein's shape so it cannot leave the liver, causing a harmful buildup.
Symptoms
Some individuals with AAT deficiency remain asymptomatic. For those who experience symptoms, they typically appear between ages 20 and 50:
- 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 standing up
- Vision problems
- Unintentional weight loss
Signs of associated liver damage include jaundice (yellowing of the skin and eyes) and leg swelling. Rarely, the condition may cause painful skin lumps or patches.
Diagnosis
Providers may test for AAT deficiency if you exhibit symptoms, have related conditions, or have a family history of the disease. In babies, testing is often prompted by signs of liver disease like jaundice or abnormal enzyme tests.
- Blood test: Checks the level of AAT protein; low levels suggest AAT deficiency.
- Genetic testing: The most certain way to confirm the diagnosis. Genotype tests look for common gene changes, while phenotype tests check for changes in the AAT protein's function.
- Lung function tests: Used to assess how well the lungs are working if they have been affected.
Treatment & Management
While there is no cure, treatments can manage symptoms and slow lung damage:
- Inhaled medicines to improve breathing
- Pulmonary rehabilitation
- Oxygen therapy
- Augmentation therapy: A lifelong treatment using donor-derived AAT protein to slow lung damage (does not prevent liver damage).
- Lung or liver transplant for severe organ damage.
To prevent or delay lung damage, it is essential to quit smoking, avoid secondhand smoke, dust, and air pollution, and consult your provider regarding alcohol consumption.