Alpha-1 Antitrypsin Phenotype
Order Code: A1AP
Fee Code: 36158
Reference Laboratory: Mayo A1APP (26953)
Due to a nationwide reagent shortage A1APP: Alpha-1-Antitrypsin Phenotype, Serum will become nonorderable effective April 13, 2022. There are currently no referral options available through Mayo Clinic Laboratories. An update will be provided when testing resumes.
The recommended alternative test is AAT: Alpha-1-Antitrypsin, Serum (order code A1AT). If the results are within reference intervals consider deferring phenotype testing until reagent shortages have been resolved. The risk for Alpha1-Antitrypsin deficiency is extremely low for a new case with normal AAT concentration.
If the provider is investigating a potential AAT deficiency phenotype or whether the patient is a carrier of a variant allele the recommended test would be A1ALC: Alpha-1-Antitrypsin Proteotype S/Z, LC-MS/MS (order code A1AL), Serum.
This alternative test employs a rapid and cost-effective liquid chromatography mass spectrometry method (proteotyping), to screen for the most common variant alleles (S and Z phenotypes) prior to considering isoelectric focusing (IEF) testing (phenotyping). The proteotype test is capable of identifying >97% of AAT deficiency cases, with 2- 3% of tests reflexing to the IEF phenotyping test to look for the rarer allele variants.