Distribution of HLA-DQB1 in Czech Patients with Central Hypersomnias.

The aim of our study was to analyze the distribution of HLA-DQB1 in Czech patients with central hypersomnias and differences between diagnostic groups of narcolepsy type 1 (NT1), type 2 (NT2), idiopathic hypersomnia (IH) and no central hypersomnia subjects (no-CH). Statistical analysis of DQB1 genotyping was performed on the cohort of 716 patients (375 men, 341 women) with reported excessive daytime sleepiness. DQB1*06:02 allele was present in 94% of the NT1 patients. The decrease of DQB1*06:03 allele was also confirmed. No other DQB1*06 allele nor any other DQB1 allele group was differently distributed in the NT1. In the cohort of NT2 patients DQB1*06:02 allele was present in 43%. Allele group DQB*05 was detected with a significantly higher frequency in this diagnostic unit. Any differences in presence of DQB1*05 alleles in NT2 patients were not reported so far. The cohort of patients with IH did not show any difference in allele distribution of DQB1 alleles/allele groups comparing to healthy controls. DQB1*06:02 allele was significantly increased in the no hypersomnia group. No other DQB1 allele/allele group had any difference in distribution in patients comparing to healthy controls. The different distribution of DQB1*06:02 and other DQB1 alleles/allele groups was detected in analyzed diagnostic groups. These results indicate that DQB1 contributes to the genetic predisposition to NT1, NT2, IH and no-CH in different manners.