Risk
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One of the most common inherited disorders (1 in 2500 in case of European ancestry; uncommon in Asians)
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Less than 10% of individuals with AAT deficiency are currently identified.
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AAT deficiency is the most common genetic cause of liver disease in neonates and children.
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About 1% to 5% of pts with COPD have AAT deficiency.
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Approximately 15% of adults with AAT deficiency develop liver cirrhosis.
Overview
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AAT is secreted in the liver as the most abundant of the serine protease inhibitors (serpins), with over 100 genetic variants of AAT identified.
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Panacinar pulm emphysema is the most common manifestation, and is the major cause of disability and death.
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Most commonly presents with slowly progressive dyspnea in mid-life, typically 2 to 3 decades earlier than do smokers with emphysema and normal AAT levels.
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Some pts present with otherwise unexplained hepatic dysfunction.
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Cigarette smoking greatly accelerates the progression of emphysema in AAT deficiency.
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AAT deficiency may present early after birth as neonatal jaundice and hepatitis, in infancy as cholestatic jaundice, or in children as liver cirrhosis or failure.
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AAT deficiency is the most common condition requiring liver transplantation in children.