Preferred test to identifiy alpha-1-antitrypsin deficiency and causative DNA and protein variants.
- Patient Preparation
- Serum separator tube AND lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Allow serum to clot completely at room temperature. Separate serum from cells ASAP or within 2 hours of collection. Transport 0.5 mL serum AND 3 mL whole blood. (Min: 0.5 mL serum AND 0.5 mL whole blood)
- Storage/Transport Temperature
- Unacceptable Conditions
- Serum: Ambient: 1 week; Refrigerated: 3 months; Frozen: 3 months (avoid repeat freeze/thaw cycles)
Whole Blood: Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month.
|Test Number||Components||Reference Interval|
|0050001||Alpha-1-Antitrypsin||Effective November 17, 2014|
| ||Alpha-1-Antitrypsin Phenotype|
Characteristics of Alpha-1-Antitrypsin (AAT) Deficiency: Coughing, wheezing, bronchiectasis, chronic obstructive pulmonary disease, emphysema, and cirrhosis.
Incidence: 1 in 3000 to 5000 North American individuals.
Inheritance: Autosomal recessive.
Cause: Two pathogenic mutations in the SERPINA1 gene on opposite chromosomes.
Clinical Sensitivity: 95 percent.
Mutations Tested: S allele (c.791A>T) and Z allele (c.1024G>A).
Methods: Genotyping performed by PCR followed by fluorescent probe melting analysis; AAT protein concentration measured using immunoturbidmetric assay; phenotyping performed by isoelectric focusing electrophoresis. Genotyping and AAT serum protein concentration determination are performed on all specimens. Protein phenotyping is only performed on specimens that have AAT protein concentrations of less than 90 mg/dL and are not homozygous or compound heterozygous for the S or Z deficiency alleles by genotyping..
Analytical Sensitivity and Specificity: 99 percent.
Limitations: SERPINA1 mutations, other than the S (c.791A>T) and Z (c.1024G>A) alleles, will not be detected. Diagnostic errors can occur due to rare sequence variations.
This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
|Component Test Code*||Component Chart Name||LOINC|
|0051259||Alpha-1-Antitrypsin S Allele||1829-1|
|0051260||Alpha-1-Antitrypsin Z Allele||1831-7|
|2001289||Alpha-1-Antitrypsin Genotype Specimen||31208-2|
- Alpha 1 Antitrypsin
- Alpha 1 Antitrypsin Genotype
- Alpha one Antitrypsin
- Alpha1-Protease Inhibitor
- Pi Typing
- Protease I