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Lab Dept:
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Chemistry
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Test Name:
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ALPHA-1-ANTITRYPSIN DEFICIENCY PROFILE
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General Information
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Lab Order Codes:
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AATP
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Synonyms:
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A1A Genotype, serum; AAT Genotype, serum
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CPT Codes:
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82103 - Alpha-1-antitrypsin; total
83890 - Molecular isolation and extraction
83896 x2 – Nucleic acid probe, each
83898 x2 - Amplification of nucleic acid, each primer pair
82104 - Alpha-1-antitrypsin; phenotype (if appropriate)
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Test Includes:
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Alpha-1-Antitrypsin genotype, serum alpha-1-antitrypsin and phenotype if appropriate. An interpretive report will be provided.
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Logistics
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Test Indications:
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Useful for confirmation of clinical diagnosis of Alpha-1-Antitrypsin deficiency and determination of the specific allelic variant. Genotyping also provides some insight as to the possible course of disease.
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Lab Testing Sections:
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Chemistry - Sendouts
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Referred to:
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Mayo Medical Laboratories (Test#: 83050)
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-6280
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651-220-6550
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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5 - 7 days, performed Monday and Wednesday
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Special Instructions:
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Both serum and plasma are required to perform this test. Please submit a Molecular Genetics Congenital Inherited Diseases Patient Information Sheet along with the specimens. Obtain this form from the laboratory (Mayo Supply T521). If informed consent is required, please submit an "Informed Consent Form for DNA testing", (Mayo Supply T576) with the specimen.
The specimens must arrive within 96 hours of collection.
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Specimen
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Specimen Type:
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Whole blood and serum
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Container:
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Red top tube and Lavender (EDTA) top tube
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Draw Volume:
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Red top: 3 mL (Minimum: 1.5 mL) blood AND
Lavender top: 1.5 mL (Minimum: 0.5 mL) blood
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Processed Volume:
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Serum (Red top): 1 mL (Minimum: 0.5 mL)
Whole Blood (Lavender top): Same as Draw Volume
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Collection:
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Routine venipuncture
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Special Processing:
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Lab Staff:
Red Top: Centrifuge specimen, remove serum aliquot into a screw-capped round bottom plastic vial. Store and ship at refrigerated temperatures. Forward promptly.
Lavender top: Do not centrifuge. Specimen should remain in original collection container. Forward unprocessed specimen at refrigerated temperatures.
The specimens must arrive within 96 hours of collection.
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Patient Preparation:
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None
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Sample Rejection:
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Mislabeled or unlabeled specimens; frozen whole blood specimens
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Interpretive
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Reference Range:
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Alpha-1-Antitrypsin Genotyping: An interpretive report will be provided.
The report will include specimen information, pedigree (when appropriate), assay information, background information, and estimate carrier risk based on test results. The report will also include quantitative levels of Alpha-1-Antitrypsin. Alpha-1 phenotyping will be included when necessary.
Alpha-1-Antitrypsin: 100 - 190 mg/dL
Alpha-1-Antitrypsin Phenotyping (when indicated): Most normal individuals have the M phenotype (M, M1 or M2). Over 99% of M phenotypes are genotypically 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. The reports for the rare alleles will indicate whether or not they have been associated with reduced quantitative levels.
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Critical Values:
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N/A
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Limitations:
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This assay will not detect all of the mutations that cause alpha-1-antitrypsin deficiency. Therefore, the absence of a detectable mutation(s) does not rule out the possibility that an individual is a carrier of or affected with this disease.
Test results should be interpreted in the context of Alpha-1-Antitrypsin quantitation, clinical findings, family history, and other laboratory data. Errors in our interpretation of results may occur if information provided to us is inaccurate or incomplete.
Rare polymorphisms exist that could lead to false-negative or false-positive results. If results obtained do not match the clinical findings, additional testing should be considered.
In rare cases, DNA alterations of undetermined significance may be identified.
A previous bone marrow transplant from an allogenic donor will interfere with testing. Call Mayo Medical Laboratories for instructions for testing patients who have received a bone marrow transplant.
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Methodology:
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Polymerase Chain Reaction (PCR), Nephelometry, and Isoelectric Focusing (when indicated)
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References:
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Mayo Medical Laboratories Web Page (March 2011)
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Updates:
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3/1/2007: Test expanded to become a genotype profile. Previously listed as a Phenotype test. Phenotyping will now only occur if necessary for a complete evaluation.
3/1/2011: EDTA draw level previously listed as 3 mL.
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