Association between migraine and the G1246A polymorphism in the hypocretin receptor 2 gene

Background.-The hypocretin receptor 2 (HCRTR2) G1246A polymorphism has been associated with the risk for cluster headache. Since the hypothalamic hypocretin/orexin system projects throughout the nervous system and affects multiple vegetative functions including generation of rhythmicity, vasomotion, autonomic symptoms as well as modulation of nociception, it may also be linked with migraine. Objective.-We thus sought to evaluate whether the HCRTR2 G1246A polymorphism is associated with the risk for migraine. Methods.-We prospectively established a cohort of 146 unrelated patients with migraine. The control group consisted of 279 healthy volunteers. We genotyped patients and controls for the HCRTR2 G1246A polymorphism and examined an association with presence or absence of migraine. Results.-Genotype and allele frequencies were not significantly different between migraine patients and controls (genotype distribution: chi(2) = 4.13, 2 df, P = .13; allele distribution: chi(2) = 0.9, 1 df, P =.34). Conclusion.-Our study does not support a major contribution of the HCRTR2 G1246A polymorphism to the pathogenesis of migraine in contrast to its effects in cluster headache.