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Unit Code 82026:
Narcolepsy Associated Antigen, Blood

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Useful For

Ruling out a diagnosis of narcolepsy

Clinical Information

Narcolepsy is a neurological condition affecting about

0.02-0.16% of African Americans, Caucasians, and Japanese.

 It can be quite disabling because it is characterized by abnormal rapid

eye movement (REM) sleep, cataplexy, hypnagogic hallucinations, and

sleep paralysis.  

 

Recent studies, have identified DQBeta1*0602 as a useful marker of

narcolepsy in African Americans, Caucasians, and Japanese. While

DQBeta1*0602 is found in virtually all narcoleptics of African Americans,

Caucasians, and Japanese, it must be clearly understood that there are

occasional patients who do not have the antigen and, more importantly,

about 25% of normal people have this gene.   

 

Because DQBeta1*0602 is present in the normal population, no test

for any HLA antigen constitutes a test for narcolepsy. A more reliable

approach would be to consider that, in an appropriate patient, the

absence of the strongly associated DQBeta1*0602, is very strong

evidence that the patient does not have narcolepsy.

Reference Values

Reported as positive or negative

Almost 100% of narcoleptics are positive; about 25% of normals

are positive

Interpretation

See "Primer Mix Combination Specificities" in Multimedia

 

The expected pattern to identify the presence of DQBeta1*0602 is an

allele-specific band in primer lanes 1 and 5.  The presence of *0610,

*0613, or *0614, identified by the presence of an allele-specific band

in lanes 2, 3, or 4, respectively, will produce an ambiguous reaction.

In these cases, the presence or absence of *0602 cannot be determined,

except where a second DQBeta1 (non-DQBeta1*06) allele has been

identified.

Cautions

No significant cautionary statements

Clinical Reference

Mignot E, Lin X, Arrigoni J, et al: DQB1*0602 and DQB1*0102 (DQ1)

are better markers than DR2 for narcolepsy in Caucasian and Black

Americans. Sleep 1994;17:S60-67

Key