HLA-DQ Typing for Narcolepsy

Test Code

12342

CPT Codes
81383

Preferred Specimen

5 mL whole blood collected in an EDTA (lavender-top) tube

Minimum Volume

3 mL

Other Acceptable Specimens

Whole blood collected in: Sodium heparin (green-top) tube, EDTA (pink-top) tube, EDTA (royal blue-top) tube, or sodium citrate (light blue-top) tube

Instructions

If submitted with any other tests, please submit separate tube for this test. Do not open tube or split sample. Shipping refrigerated is acceptable.

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: 7 days
Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Received frozen • Clotted

Methodology
Polymerase Chain Reaction Amplification • Sequence Specific Oligonucleotide Probes

Setup Schedule

Set up: Daily; Report available: 8 days

Reference Range

See Laboratory Report

Clinical Significance

The HLA-DQB1*06:02 is strongly associated with narcolepsy, a neurological condition associated with excessive daytime sleepiness, cataplexy, and other nighttime sleep disorders. Presence of HLA-DQB1*06:02 by itself is not diagnostic. It is used along with clinical history and sleep studies in the diagnosis of narcolepsy. Narcolepsy is associated with HLA DR15 (DR2) and DQB1*0602. DQB1*0602 was found to be a more sensitive marker for narcolepsy than DRB1*15 across all ethnic groups. DQB1*0602 frequency was strikingly higher in patients with cataplexy versus patients without cataplexy (76.1% in 421 patients versus 40.9% in 88 patients).

Reference:
E Mignot, et al. Sleep.1997 Nov;20(11):1012-20

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.