What genetic variant increases the risk of narcolepsy?

Approximately 90-99% of people with narcolepsy carry a variant of the HLA-DQB1 gene known as the HLA-DQB1*06:02 allele.

•  Two copies of HLA-DQ1b*06:02 = 7X – 25X increased risk of narcolepsy (or potentially up to 250X increased risk!)
•  One copy of HLA-DQB1*06:02 + an alternative HLA-DQB1 allele = 3X increased risk (depending on the risk or protective affect of the alternative allele)