Alpha-1-Antitrypsin Genotype, Serum and Whole Blood

A1AT; Alpha-1 Antitrypsin; AAT; Alpha-1 Protease Inhibitor (PI) Mutation; AAT Deficiency; Alpha-1 Antitrypsin Genotype; AAT Genotype, Mutation

A1AT genotype; Alpha 1 Antitrypsin Phenotype

Testing eligibility
Serum A1AT concentration must be provided to order this test.
Testing is only available if one or more of the following is/are applicable.

• Serum A1AT concentration is ≤ 1.15 g/L.
• There is a documented family history of A1AT deficiency.
• There is liver disease and A1AT concentration is < 1.50 g/L.
• The patient has COPD that is unusually severe and unexplained.

Reflex Test Protocol

1. Targeted Genotyping by melting curve analysis for Z and S variants.
   No further testing is done if the preliminary diagnostic test result agrees with the serum A1AT level.
2. Phenotype by Isoelectric Focussing (IFE) is performed if there is:
   • A discordance between the serum/clinical phenotype and the targeted genotype
   • Targeted genotype is MZ (to allow detection of FZ)
   • When the testing is ordered for prenatal counselling
3. Gene Sequencing will be performed when the clinical information/targeted genotyping/IFE suggest M Malton or another rare allele not detectable by targeted genotyping or IFE.

Additional information is also available here.