A1AT has more than 100 allele variants that result in unique A1AT blood plasma levels. M1-M6 are considered normal variants of the enzyme and result in plasma levels ≥0.9 mg/mL. Null mutations are not common. Additionally, about 70% of aberrant the molecules are degraded, and the remainder are polymerized into a conformation that can induce cell stress and inflammation. These phenomena can lead to disease states such as chronic liver injury, fibrosis, and cirrhosis.