Alpha-1 antitrypsin deficiency | |
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Structure of Alpha 1-antitrypsin | |
Classification and external resources | |
Specialty | Pulmonology, medical genetics |
ICD-10 | E88.0 |
ICD-9-CM | 273.4 |
OMIM | 107400 |
DiseasesDB | 434 |
MedlinePlus | 000120 |
eMedicine | med/108 |
Patient UK | Alpha 1-antitrypsin deficiency |
MeSH | D019896 |
GeneReviews |
Alpha-1 antitrypsin deficiency (α1-antitrypsin deficiency, A1AD) is a genetic disorder that causes defective production of alpha 1-antitrypsin (A1AT), leading to decreased A1AT activity in the blood and lungs, and deposition of excessive abnormal A1AT protein in liver cells. There are several forms and degrees of deficiency; the form and degree depend on whether the sufferer has one or two copies of a defective allele. In the literature it has been described as either a recessive or co-dominant trait as there is some evidence that smoking heterozygotes are affected. Severe A1AT deficiency causes panacinar emphysema or COPD in adult life in many people with the condition (especially if they are exposed to cigarette smoke). The disorder can lead to various liver diseases in a minority of children and adults, and occasionally more unusual problems. It is treated through avoidance of damaging inhalants and, in severe cases, by intravenous infusions of the A1AT protein or by transplantation of the liver or lungs. It usually produces some degree of disability and reduces life expectancy.
Symptoms of alpha-1 antitrypsin deficiency include shortness of breath, wheezing, rhonchi, and rales. The patient's symptoms may resemble recurrent respiratory infections or asthma that does not respond to treatment. Individuals with A1AD may develop emphysema during their thirties or forties even without a history of significant smoking, though smoking greatly increases the risk for emphysema. A1AD causes impaired liver function in some patients and may lead to cirrhosis and liver failure (15%). In newborns, alpha-1 antitrypsin deficiency has indicators that include early onset jaundice followed by prolonged jaundice. It is a leading indication for liver transplantation in newborns.