Genetic studies in the sleep disorder narcolepsy

Area of Science:

• Neurology
• Sleep Medicine
• Genetics

Background:

• Narcolepsy is a chronic neurological disorder causing excessive daytime sleepiness and REM sleep abnormalities.
• Human narcolepsy research identified HLA alleles (DQB1*0602, DQA1*0102), suggesting a potential autoimmune link.
• Genetic factors beyond HLA are implicated in narcolepsy's development.

Purpose of the Study:

• To investigate the genetic underpinnings of narcolepsy.
• To explore the potential autoimmune basis of narcolepsy.
• To identify the gene responsible for narcolepsy in a canine model (canarc-1).

Main Methods:

• Analysis of human narcolepsy cases to identify predisposing HLA alleles.
• Study of a canine model of narcolepsy exhibiting autosomal recessive inheritance (canarc-1).
• Positional cloning using a canine genomic BAC library to isolate the canarc-1 gene.

Main Results:

• Specific HLA alleles (DQB1*0602, DQA1*0102) are associated with human narcolepsy.
• In canines, narcolepsy (canarc-1) follows a single autosomal recessive trait with full penetrance.
• A marker tightly linked to canarc-1 has been identified, facilitating gene isolation.

Conclusions:

• While HLA associations exist, the autoimmune hypothesis for narcolepsy remains unconfirmed.
• The identification of canarc-1 in dogs offers a valuable model for understanding narcolepsy.
• Cloning the canarc-1 gene may significantly advance the understanding of fundamental sleep mechanisms.