HLA DQ 6 ( Diabetes/ Narcolepsy)

Category: Immunogenetics
Test Code: 144
Disease: Pharmacogenetics/Ocular Immunogenetics
Methodology: Polymerase chain reaction (PCR) with Sequence Specific Primers
Reference Range: Reported positive or negative.
CPT Code: 83891; 83898 (x31); 83894; 83912.
Schedule / Turnaround Time: Assay performed daily. Report availability is within 48 hours from the time of specimen receipt.
Specimen Requirements:

Specimen must be kept in ambient temperature and should not be refrigerated or frozen. Collect 5 ml of blood in a lavender top Hemogard (EDTA) tube.

Sample Stability:

Sample is stable at ambient temperature and should be analyzed within 76 hours.


Insulin dependent diabetes mellitus is positively associated with DQ8, DQ2, and DQ6 (DQB1*06:04), and negatively associated with DQ6 (DQB1*06:02), DQ6 (DQB1*06:03), and DQ7 in Swedish Caucasians. The protection conferred by DQ6 (DQB1*06:02) is stronger in younger individuals and there is decrease in the effect of protection with increasing age. Three dimensional modeling of the susceptible DQ6 (DQB1*06:04) and protective DQ6 (DQB1*06:02), which share the same DQA chain (DQA1*01:02) but differ in the DQB chain at 6 residues, identifies residue 57 and 70 to be important for protection.