α1-Antitrypsin Phenotyping (PI Typing)
Immunology
Sample and container requirements
Serum
Minimum volume required
1mL serum
Special requirements
None
Patient preparation
None
Sample viability
Turnaround time
14 days
Reference range
Not applicable
Clinical guidance
Investigation of genetic origin of α1-antitrypsin deficiency. Used in family screening for first degree relatives when a deficiency has been identified. Genetic variants of A1AT are characterised by their different electrophoretic mobilties i.e. M, S or Z. The M allele is the most common and is associated with normal protein levels. The Z and S alleles are the most clinically significant deficiency variants; individuals who are homozygous for the Z allele (PI*ZZ) are at the highest risk for developing severe lung or liver disease.
Notes
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This information was last updated on 19 August 2026