Test Details

Mnemonic

AGDEL

Ordering Code

3426420

CPT-4 Code(s)

81269

Specimen Information

Patient Preparation

This test requires a physician attestation form that patient consent has been received if the
ordering medical facility is located in AK, DE, FL, GA, IA, MA, MN, NV, NJ, OR, SD or VT or test is
performed in MA.

Collect

Lavender EDTA

Specimen Preparation

Send 5.0 mL whole blood at room temperature. Specimen stability is crucial. Store and ship at room temperature immediately.

Alternate Specimen

Whole blood: yellow ACD B, green sodium
Heparin Amniotic fluid (20.0 mL; 5.0 mL minimum)
Cultured Cells
Chorionic villus sampling (20 mg; 10 mg minimum)

Minimum Volume

3.0 mL

Transport Temperature

Room temperature

Rejection Criteria

Sample received frozen

Stability

Whole Blood:
Room temperature: 30 days
Refrigerated: 30 days
Frozen: 30 days

Other specimens:
Room temperature: 48 hours
Refrigerated: Unacceptable
Frozen: Unacceptable

Methodology

Multiplex PCR, Capillary Electrophoresis
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Reference Range

Alpha-Globin Del/Duplicate (UOM)
Alpha-globin is an essential component
of the hemoglobin tetramer, beginning
in the early stages of embryonic development.
Deletion mutations involving one or both
of the alpha-globin genes (designated
HBA1 (alpha-1) and HBA2 (alpha-2))
in the alpha-globin gene cluster (located
on chromosome 16p13) lead to reduced
production of alpha-globin chains, and are
the major cause of alpha-thalassemia. The
severity of symptoms is dependent on the
number of functional alpha-globin
genes remaining. In the assay,
multiplex-polymerase chain reaction (PCR)
amplification of fragments specific for the
5'-end, interior, and 3'-end of the
alpha1- and alpha2-globin genes is
carried out in the presence of
fluorescently-labeled primers. In addition,
fragments representing the HS40/locus control
region (LCR), the alpha-globin pseudogene,
as well 3 non-alpha globin fragments used
as internal controls, are co-amplified.
Amplification products are analyzed on
an automated capillary DNA sequencer.

This assay cannot detect single nucleotide
substitutions and small insertion/deletion
mutations in the alpha-globin gene cluster.
Since genetic variation and other factors can
affect the accuracy of direct mutation testing,
the results of this testing should always be
interpreted in light of clinical and familial data.
For assistance with the interpretation of the
results, please contact your local Quest Diagnostics
genetic counselor or call 1-866-Geneinfo (436-3463).
This test was developed and its performance
characteristics have been determined by
Quest Diagnostics Nichols Institute, San Juan
Capistrano. Performance characteristics refer
to the analytical performance of the test.
Note: Results from this assay are not useful for
carrier determination. Carriers usually have levels
in the normal range.
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Performing Laboratory

Quest SJC
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New York DOH Approval Status

No
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