Use of PCR with sequence-specific primers for high-resolution human leukocyte antigen typing of patients with narcolepsy.

BACKGROUND

Narcolepsy is a neurologic disorder characterized by excessive daytime sleepiness, symptoms of abnormal rapid eye movement (REM) sleep, and a strong association with HLA-DRB11501, -DQA10102, and -DQB10602. Here, we investigated the clinico-physical characteristics of Korean patients with narcolepsy, their HLA types, and the clinical utility of high-resolution PCR with sequence-specific primers (PCR-SSP) as a simple typing method for identifying DRB115/16, DQA1, and DQB1 alleles.

METHODS

The study population consisted of 67 consecutively enrolled patients having unexplained daytime sleepiness and diagnosed narcolepsy based on clinical and neurological findings. Clinical data and the results of the multiple sleep latency test and polysomnography were reviewed, and HLA typing was performed using both high-resolution PCR-SSP and sequence-based typing (SBT).

RESULTS

The 44 narcolepsy patients with cataplexy displayed significantly higher frequencies of DRB11501 (Pc= 0.003), DQA10102 (Pc=0.001), and DQB10602 (Pc=0.014) than the patients without cataplexy. Among patients carrying DRB11501-DQB10602 or DQA10102, the frequencies of a mean REM sleep latency of less than 20 min in nocturnal polysomnography and clinical findings, including sleep paralysis and hypnagogic hallucination were significantly higher. SBT and PCR-SSP showed 100% concordance for high-resolution typing of DRB1*15/16 alleles and DQA1 and DQB1 loci.

CONCLUSIONS

The clinical characteristics and somnographic findings of narcolepsy patients were associated with specific HLA alleles, including DRB11501, DQA10102, and DQB10602. Application of high-resolution PCR-SSP, a reliable and simple method, for both allele- and locus-specific HLA typing of DRB115/16, DQA1, and DQB1 would be useful for characterizing clinical status among subjects with narcolepsy.