Background Type 1 Narcolepsy is a severe hypersomnia caused by a specific loss of neurons producing hypocretin/orexin in the hypothalamus and affecting 1/3000 individuals. In 2009/2010 immunization towards pandemic H1N1 Influenza-A campaign was launched and the vaccine used in Northern European countries associated with increased risk for narcolepsy. Methods We built a multilocus genetic risk score with established narcolepsy risk variants using whole genome sequencing and exome sequencing data from 7,000 individuals to examine the genetic load for narcolepsy in 75 individuals with vaccination related narcolepsy, a third of all cases from Finland. Results Previously discovered risk variants had strong predictive power (P Discussion Our findings suggest that genetic risk factors have a major role in regulating predisposition for narcolepsy and genetic risk score gives high predictive power to detect individuals with high risk for narcolepsy.
