Alpha-1 antitrypsin is a protein that is made in the liver and then released into the bloodstream. Sometimes a gene mutation produces an abnormal form of this protein which cannot be released from the liver, which means it cannot enter the bloodstream.
Alpha-1 antitrypsin's job is to protect tissues in the body from being digested by enzymes released from inflammatory cells. Enzymes may then attack the lung and / or liver tissue.
In very young children, alpha-1 antitrypsin then accumulates in the liver, causing damage to the liver. Approximately 10 percent of infants born with the severe deficiency have liver disease that is fatal without a liver transplant.
Alpha-1-antitrypsin deficiency is an inherited condition and does not appear unless a person receives the same defective gene from both parents. If both parents carry an abnormal gene for alpha-1 antitrypsin deficiency disease there is:
- A 25 percent chance their child will develop the disorder
- A 50 percent chance their child will receive one defective gene from one of the parents, which means the child will not show symptoms of the disorder but is a "carrier"
- A 25 percent chance their child will receive both normal genes, one from each parent, and will be unaffected