Genetics reference · Respiratory Medicine
Alpha-1 antitrypsin deficiency
MedlinePlus Genetics, National Library of Medicine · Retrieved 2026-10-13
Alpha-1 antitrypsin deficiency is an inherited disorder that may cause lung disease and liver disease. The signs and symptoms of the condition and the age at which they appear vary among individuals. People with alpha-1 antitrypsin deficiency usually develop the first signs and symptoms of lung disease between ages 25 and 50. The earliest symptoms are shortness of breath following mild activity, reduced ability to exercise, and wheezing. Other signs and symptoms can…
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Reference details
- Inheritance patterns
- Autosomal recessive
- Other names
- AAT; AATD; Alpha-1 protease inhibitor deficiency; Alpha-1 related emphysema; Genetic emphysema; Hereditary pulmonary emphysema; Inherited emphysema
- NLM review date
- 2009-08
- NLM publication date
- 2025-04-03
Description
Alpha-1 antitrypsin deficiency is an inherited disorder that may cause lung disease and liver disease. The signs and symptoms of the condition and the age at which they appear vary among individuals.
People with alpha-1 antitrypsin deficiency usually develop the first signs and symptoms of lung disease between ages 25 and 50. The earliest symptoms are shortness of breath following mild activity, reduced ability to exercise, and wheezing. Other signs and symptoms can include unintentional weight loss, recurring respiratory infections, and fatigue. Affected individuals often develop emphysema, which is a lung disease caused by damage to the small air sacs in the lungs (alveoli). Characteristic features of emphysema include difficulty breathing, a hacking cough, and a barrel-shaped chest. Smoking or exposure to tobacco smoke accelerates the appearance of emphysema symptoms and damage to the lungs.
About 10 percent of infants with alpha-1 antitrypsin deficiency develop liver disease, which often causes yellowing of the skin and whites of the eyes (jaundice). Approximately 15 percent of adults with alpha-1 antitrypsin deficiency develop liver damage (cirrhosis) due to the formation of scar tissue in the liver. Signs of cirrhosis include a swollen abdomen and jaundice. Individuals with alpha-1 antitrypsin deficiency are also at risk of developing a type of liver cancer called hepatocellular carcinoma.
In rare cases, people with alpha-1 antitrypsin deficiency develop a skin condition called panniculitis, which is characterized by hardened skin with painful lumps or patches. Panniculitis varies in severity and can occur at any age.
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Source date: 2009-08. Retrieved: 2026-10-13. Text has been organized for reading; this import has not been independently reviewed by a clinician. It is not individualized medical advice.
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