How Common is α -1-Antitrypsin Deficiency?

Discussion α-1-Antitrypsin Deficiency (A1AT) is a common single-gene mutation disease that is homozygous recessive. The normal allele is called M and the most common abnormal allele is Z. There are other alleles though. The gene codes for one of the primary protease inhibitors in the serum, thus those who are homozygous for the Z gene are sometimes referred to as “PIZZ” or “PIZ.” α-1-Antitrypsin is found in all body tissues but is especially important in the serum and lung. As noted it is one of the primary neutrophil protease inhibitors in the serum, and acts to neutralize these enzymes when they leak into the extracellular fluid during inflammation. The Z mutation causes the synthesis of an abnormal protein which is retained in the hepatocytes and accumulates instead of being secreted. This can cause chronic liver disease including cirrhosis and hepatic failure. The Z mutation also causes emphysema in young to middle-aged adults. The natural history of the disease process can be quite variable. Pediatric patients may be asymptomatic or present with cholestatic hepatitis, hepatomegaly, and nutrition/growth problems. Other important problems include chronic liver disease with cirrhosis and fibrosis (lifetime risk ~50% for ZZ patients). Hepatocellular carcinaoma risk is increased. The lungs are particularly sensitive to A1AT. Lung infections, asthma, and emphasema occur and smoking or second-hand smoke increases the risk of serious lung dis...
Source: PediatricEducation.org - Category: Pediatrics Authors: Tags: Uncategorized Source Type: news