HLA and hypocretin studies in Korean patients with narcolepsy.
OBJECTIVE
Very few studies have evaluated narcolepsy in Asian countries, outside of Japan. Our goal was to study narcolepsy at the genetic, clinical and pathophysiological level in Korea.


METHODS
Prospective study of consecutive patients and age matched controls. Clinical data ascertained from the Stanford Sleep Inventory, Polysomnography and MSLT data, as well as clinical notes. High resolution DRB1 and DQB1 typing in all subjects and studies of CSF hypocretin-1 was also evaluated in a subset of patients.


METHODS
20 patients diagnosed at St. Vincent and Korea University Hospitals (Seoul, Korea). 21 Korean control subjects.


METHODS
N/A.


RESULTS
For narcoleptic subjects, mean age was 28.2 years old and 45% were female. Mean BMI was 23.9+/-3.4 kg/m2, a significantly higher value than that expected in an age- and sex-matched sample (p<0.01). All patients had sleepiness and cataplexy while the prevalence of other symptoms ranged from 60-75%. All but 2 subjects were HLA-DR15 (DR2), DQB1*0602 positive (90%). This high DQB1*0602 percentage compared with 24% DQB1*0602 positivity in 21 control Koreans. Protective effects were observed for the DQB1*0601 and DRB1*0406 alleles, Hypocretin (orexin) CSF studies were also performed in 6 cataplectic subjects, all of which had undetectable CSF hypocretin levels. Two of these subjects had started narcolepsy less than 1 year before analysis yet had undetectable hypocretin levels.


CONCLUSIONS
These results illustrate the similarity of narcolepsy-cataplexy in Korea in comparisons with other more studied populations. We also identified a new potential HLA protective subtype, HLA-DRB1*0406.
Hong
Seung-Chul
SC
Department of Neuropsychiatry, St. Vincent's Hospital, Catholic University of Korea, Suwon.
Leen-Kim
Park
Soo-A
SA
Han
Jin-hee
JH
Lee
Sung-Pil
SP
Lin
Ling
L
Okun
Michele
M
Nishino
Seiji
S
Mignot
Emmanuel
E
D000293:Adolescent; D000328:Adult; D002352:Carrier Proteins / Q000378:metabolism*; D002648:Child; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007723:Korea / Q000453:epidemiology; D008297:Male; D009290:Narcolepsy / Q000453:epidemiology / Q000276:immunology* / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D000068797:Orexins; D011446:Prospective Studies
D002352:Carrier Proteins; C000596229:HCRT protein, human; D006680:HLA Antigens; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins