genetics

Last reviewed 01/2018

95% of white patients with narcolepsy have the HLA DR2 (HLA DR 15 in the new terminology) genotype.

100% of black patients with narcolepsy have the HLA DQ w1 (HLA DQ w6 in the new terminology) genotype.

The environment may be important because there is only a 25% concordance for narcolepsy in monozygotic twins.

The risk of narcolepsy in first degree relatives of sufferer is 1-2% (a relative risk of 40).