Alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin is a protein that protects the lungs and is made in the liver. The main deficiency variant (the Z variant) lowers its levels, and two copies can lead to early emphysema (much worse with smoking) and liver problems.

Possible results

Normal alpha-1 antitrypsin. You don't carry the main deficiency variant, so your body makes normal levels of alpha-1 antitrypsin, a protein that protects the lungs. From what this variant shows your risk of alpha-1 antitrypsin deficiency is not raised.

Alpha-1 antitrypsin carrier. You carry one copy of the main deficiency variant, so you make somewhat less of the lung-protecting protein alpha-1 antitrypsin. Most carriers stay healthy, but the risk of lung problems is a bit higher, and avoiding smoking is especially worthwhile. You can also pass the variant on.

Alpha-1 antitrypsin deficient. You have two copies of the main deficiency variant, which gives much lower levels of alpha-1 antitrypsin, the protein that shields your lungs. This raises the risk of early emphysema, greatly worsened by smoking, and can affect the liver. It's worth discussing with a doctor, and staying away from smoke is the single most protective step.

Evidence & sources

Across global populations, fewer than 1% of people carry two copies of this variant, and about 97% carry none.

This variant appears in 1 published genetic study: PubMed 39024449.

Related

G6PD deficiency (favism) · Gaucher disease type 1 (carrier) · Hereditary hemochromatosis (HFE gene)