HLA-DR15(DR2) AND DQB1-ASTERISK-0602 TYPING STUDIES IN 188 NARCOLEPTIC PATIENTS WITH CATAPLEXY

Narcolepsy is considered a homogeneous clinical entity when excessive daytime sleepiness and cataplexy are present. Cataplexy is a polymorph ic symptom that can be very mild and is thus subjectively defined. The Multiple Sleep Latency Test (MSLT) is widely used as a diagnostic tes t for narcolepsy. A short mean sleep latency and multiple sleep onset REM periods (SOREMPs) are typically observed in narcoleptic patients. The discovery of a tight association of narcolepsy with HLA class II a ntigens offers a unique opportunity to explore the respective value of the MSLT or of the presence of clear-cut cataplexy in defining an eti ologically homogeneous group of narcoleptic patients. In this study, w e carried out HLA typing for DR15(DR2) and DQB10602 in 188 narcolepti c patients with cataplexy in three ethnic groups (24 Asians, 61 Blacks , and 103 Caucasians). These results confirm the importance of DQB106 02 typing rather than DR15 (DR2) typing in Black narcoleptic patients and demonstrate that the presence of clear-cut cataplexy is a better p redictor for DQB10602 positivity than the presence of abnormal MSLT r esults.