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| DiseaseID |
HGD16 |
| Genetic
Disorder |
Alpha-1-antitrypsin deficiency
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| Gene
Name |
SERPINA1 gene, |
| Description |
Alpha-1 antitrypsin deficiency is an inherited disorder that can cause lung disease in adults and liver disease in adults and children. Alpha-1 antitrypsin (AAT) is a protein that protects the lungs. The liver usually makes the protein, and releases it into the bloodstream. Because of a gene problem, some people have little or none of it. Not having enough AAT puts you at risk of emphysema or liver problems. Three in four adults with a severe deficiency will get emphysema, some when they are younger than 40. If you smoke, you increase your risk. Children with AAT deficiency can develop liver problems that last their whole lives.
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| Symptoms |
Since alpha-1 antitrypsin deficiency is inherited, it is present at birth.
Individuals with the disorder are at increased risk of developing:
• lung disease – damage of the lung tissues causes emphysema, a lung disease that results in shortness of breath. Emphysema may begin sooner, or be made worse, by smoking.
• liver disease – damage of the liver tissues causes cirrhosis (scarring of the liver). Excessive pressure in the portal vein that carries blood to the liver (called portal hypertension), a serious condition, may develop. Liver cancer is also a long-term risk with cirrhosis.
• panniculitis, which refers to a group of skin conditions that involve inflammation of the fat under the skin.
Symptoms of alpha-1 antitrypsin deficiency may develop in infancy or childhood. Some individuals may have their symptoms get worse over time. Many individuals with the disorder, though, do not develop symptoms, or their symptoms do not worsen.
The World Health Organization (WHO), American Thoracic Society (ATS) and the European Respiratory Society (ERS) recommend that all individuals with chronic obstructive lung disease or unexplained liver disease be tested for alpha-1 antitrypsin deficiency.
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| Causes |
Alpha-1 antitrypsin deficiency results from a genetic defect. The mechanism that causes associated liver disease and emphysema in some people with this deficiency is not known. However, some evidence suggests that it may be related to inflammation.
Studies now show that Alpha-1 antitrypsin deficiency may be more common than once thought. Approximately 75% of adults with severe deficiency will develop emphysema, which often begins before 40 years of age. Smoking can increase the risk. |
| Diagnosis |
There are two types of simple laboratory blood tests for alpha-1 antitrypsin. The alpha-1 antitrypsin level in the blood can be checked. In general, individuals with apha-1 antitrypsin deficiency tend to have an AAT level of less than 50 mg/dL. Genetic testing can look for an abnormal AAT gene to help confirm the diagnosis.
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| Treatment |
Treatment focuses on maintaining and improving the health of the lungs and liver. If the liver is severely damaged, liver transplantation may be necessary. Liver damage does not usually occur in the transplanted liver, and the new liver is able to produce alpha-1 antitrypsin. Medications to treat emphysema, preventing lung infections, and getting individuals to quit smoking all help improve lung function. If the lungs are severely damaged, lung transplantation may be necessary.
In addition to treatment of lung and liver disease, specific treatment of alpha-1 antitrypsin deficiency consists of weekly infusions of purified human plasma alpha-1 antitrypsin (called augmentation therapy). The goal of this treatment is to raise and maintain the levels of alpha-1 antitrypsin in the body. Several preparations, including AAT, Prolastin, Aralast and Zemaira are available for augmentation therapy. |
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