Narcolepsy (HLA-DRB1*15:01, HLA-DQB1*06:02)

EDTA blood or buccal swab, 0.5ml

EDTA blood or buccal swab, 0.5ml

Narcolepsy is a chronic neurological disorder characterised by disturbed regulation of the sleep-wake rhythm. People with narcolepsy suffer from excessive daytime sleepiness and may experience uncontrollable sleep attacks in which they suddenly and unexpectedly fall asleep, even during activities such as eating, working or talking. In addition to excessive daytime sleepiness, people with narcolepsy may also have other symptoms, such as cataplexy, in which they suddenly lose control of muscles and become temporarily paralysed. Other symptoms may include sleep paralysis (temporary inability to move or speak when falling asleep or waking up) and vivid dreams or hallucinations when falling asleep or waking up. Narcolepsy is a chronic condition for which there is no cure, but with medication and good sleep hygiene, symptoms can be controlled and quality of life improved.

Narcolepsy usually begins in adolescence or early adulthood. Although the exact mechanisms are unclear, it is thought to be an autoimmune disease in which the hypocretin-producing neurons in the lateral hypothalamus are attacked.

Narcolepsy is strongly associated with the HLA system (human leukocyte antigen). In particular, the specific genetic variant HLA-DQB1*06:02 is found in more than 90% of patients with narcolepsy with cataplexy (narcolepsy type 1) and in 40% of patients with narcolepsy without cataplexy (narcolepsy type 2). The HLA-DR1*15:01 variant is also strongly associated with the occurrence of narcolepsy.
Since these HLA subtypes are also found in 12-38% of the general population without narcolepsy symptoms, the results of HLA subtyping should be considered as predisposing factors, but these alone are not sufficient for the diagnosis of narcolepsy.