Alpha-1 Antitrypsin Phenotype

Diagnostic Use

Identification of homozygous and heterozygous phenotypes of the alpha-1 antitrypsin deficiency.

Alpha-1 antitrypsin phenotyping will be reflex added to all alpha-1 antitrypsin requests for levels if the level is ≤ 1.2 g/L.

Alpha-1 antitrypsin (AAT) is the most abundant serum protease inhibitor and inhibits trypsin and elastin, as well as several other proteases. The release of proteolytic enzymes from plasma onto organ surfaces and into tissue spaces results in tissue damage unless inhibitors are present. Congenital deficiency of AAT is associated with the development of emphysema at an unusually early age and with an increased incidence of neonatal hepatitis, usually progressing to cirrhosis.

Most normal individuals have the M phenotype (M, M1, or M2). Over 99% of M phenotypes are genetically MM. In the absence of family studies, the phenotype (M) and quantitative level can be used to infer the genotype (MM). The most common alleles associated with a quantitative deficiency are Z and S.


Protein Lab

Delphic Registration Code


Constituent Tests

Turnaround Time

14 days

Test Code