Association between human leukocyte antigen class II-DR-DQ and narcolepsy: a case control study

Area of Science:

• Immunogenetics
• Neurology
• Sleep Medicine

Background:

• Narcolepsy, a sleep disorder, has an unknown cause but is linked to human leukocyte antigen (HLA) genes.
• Investigating HLA class II-DR-DQ alleles is crucial for understanding narcolepsy's genetic basis.

Purpose of the Study:

• To examine the association of HLA class II-DR-DQ alleles with narcolepsy type 1 (NT1) and narcolepsy type 2.
• To compare demographic, clinical, and laboratory features of narcolepsy patients with and without the DQB1*06:02 allele.

Main Methods:

• A case-control study involving 21 NT1 patients, 16 narcolepsy type 2 patients, and 100 controls.
• HLA-DRB1 and DQB1 alleles were identified using sequence-based typing and PCR-sequence-specific oligonucleotide methods.
• Nocturnal polysomnography and Multiple Sleep Latency Test were conducted on all participants.

Main Results:

• The DQB1*06:02 allele was significantly more frequent in NT1 patients (61.9%) compared to narcolepsy type 2 (18.8%) and controls (18.0%).
• The HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 haplotype was associated with NT1 in Brazilian patients.
• DQB1*06:02 positive patients exhibited shorter rapid eye movement sleep latencies during polysomnography.

Conclusions:

• A strong association exists between HLA-DQB1*06:02, the specific haplotype, and NT1.
• Shorter REM sleep latencies were observed in patients with the DQB1*0602 allele.
• DQB1 genotyping is recommended for narcolepsy screening.