Alpha-1 Antitrypsin Deficiency: Gene Mutation, Symptoms, Treatment, and Life Expectancy

*Facts medically reviewed by Charles P. Patrick, MD, PhD

• Alpha1 antitrypsin deficiency (AATD, antitrypsin deficiency, or alpha 1 antitrypsin deficiency) is a disorder (disease) that causes the alpha-1 antitrypsin (AAT) protein to be reduced or missing from the blood. This protein is necessary for healthy lungs, and the body uses it to protect the lungs from damage. If a person has low or no levels of AAT their lungs may be damaged.
• Statistically, the disorder affects about one in 1500 to 3500 individuals with European ancestry. It is uncommon in Asians.
• The signs and symptoms most people experience with this deficiency are:
  • Chronic cough
  • Emphysema
  • COPD
  • Liver failure
  • Hepatitis
  • Hepatomegaly (enlarged liver)
  • Jaundice
  • Cirrhosis
• Mutations in the gene termed SERPNA1 cause alpha –1 antitrypsin deficiency.
• A patient with lung or liver disease like COPD (chronic obstructive pulmonary disease) with no obvious cause maybe AATD deficient.
• Doctors can confirm the diagnosis of this deficiency with blood tests or liver biopsy.
• How doctors treat AATD depends on the patient’s signs and symptoms. Examples of treatments include:
• Bronchodilators and inhaled steroids can help lung problems.
• Intravenous use of purified human ATT (Prolastin) raise the level of ATT in the blood and lungs (augmentation therapy) - end stage lung and liver disease may need transplantation of these organs as a definitive treatment.
• Management of AATD involves pulmonary function tests, liver function monitoring and yearly vaccinations against influenza. Moreover, doctors recommend that patient’s with the deficiency be vaccinated against hepatitis A and B, and pneumococcus.
  • Stop smoking or reduce exposure to secondhand smoke.
  • Reduce exposure to environmental pollutants.
• The prognosis for someone with this problem is quite variable, and is related to the development and progression of severity of the symptoms. However, many people have a somewhat shortened lifespan. If the symptoms are severe, the prognosis can be very poor.
• Medical professionals refer to alpha-1 antitrypsin deficiency.
  • AAT
  • AATD
  • Alpha-1 proteinase inhibitor
  • Alpha-1 related emphysema
  • Genetic emphysema
  • Hereditary pulmonary emphysema
  • Inherited emphysema

Alpha-1 antitrypsin deficiency (AATD) is a disorder that causes a deficiency or absence of the alpha-1 antitrypsin (AAT) protein in the blood. AAT is made in the liver and sent through the bloodstream to the lungs, to protect the lungs from damage. Having low levels of ATT (or no ATT) can allow the lungs to become damaged, making breathing hard. Age of onset and severity of AATD can vary based on how much ATT an affected person is missing. In adults, symptoms may include shortness of breath; reduced ability to exercise; wheezing; respiratory infections; fatigue; vision problems; and weight loss. Some people have chronic obstructive pulmonary disease (COPD) or asthma. Liver disease (cirrhosis) may occur in affected children or adults. Rarely, AATD can cause a skin condition called panniculitis.[1] AATD is caused by mutations in the SERPINA1 gene and is inherited in a codominant manner.[2] Treatment is based on each person's symptoms and may include bronchodilators; antibiotics for upper respiratory tract infections; intravenous therapy of AAT; and/or lung transplantation in severe cases.[1][3]

The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies.