The reasons behind the occurrence of narcolepsy were not ascertained for several years after the signs and symptoms of the illness were discovered. However, in the recent past, the likelihood of exhibiting this disorder has been strongly linked with certain specific conditions. In particular, specific genetic conditions are believed to be the main cause of narcolepsy.
The predisposition of a person to narcolepsy is mainly attributed to the different variants of the special ‘HLA genes’ present on Chromosome 6 as a part of the HLA complex. However, HLA complex has no role as such in the development of the narcoleptic condition. Mutations in the HLA genes trigger a specific auto-immune reaction against some of the brain’s special neurons that are involved in protein production. Consequently, levels of important proteins, such as orexin and hypocretin, which control sleep patterns and appetite, get significantly reduced in the brain causing narcoleptic symptoms. The genetic cause of narcolepsy has been proven by the study done at the Stanford University’s School of Medicine in 2009. A similar research in Australia in 2004 provided strong evidence to corroborate the fact that narcolepsy is an autoimmune disorder associated with linkage disequilibrium in the HLA-DQB1, HLA-DQ1, and HLA-DR2 genotypes.
In spite of enough experimental proof available to establish that some specific forms of human narcolepsy are inherited and caused due to genetic variations, their mode of inheritance from one generation to another is still not known clearly. Some cases of narcolepsy have been reported to be associated with other genetic conditions, such as Prader Willi Syndrome (PWS) and Neimann Pick Disease.
Also, the exact association between narcolepsy and the mechanism of neural control of normal sleep is still poorly understood. The narcoleptic sleep in humans is marked by the propensity of the patient to go suddenly and unexpectedly from a waking state to REM sleep, with little or almost negligible intervening non-REM sleep. The exact mechanism that causes this peculiar sleep pattern is still under research.
More Articles :