Lack of association between the 3092 T-->C Clock gene polymorphism and cluster headache.

Recent studies suggested that genetic factors play a role in cluster headache (CH). However, the type and the number of genes involved in the disease are still unclear. We performed an association study in a cohort of Italian CH patients to evaluate whether a particular allele or genotype of the Clock gene would modify the occurrence and the clinical features of the disease. One hundred and seven CH patients, diagnosed according to the International Classification of Headache Disorders, 2nd Edition, (ICHD-II) criteria, and 210 healthy age, sex and ethnicity-matched controls were genotyped for the 3092 T-->C Clock gene polymorphism (also known as 3111 T-->C). Phenotype and allele frequencies were similarly distributed in CH patients and controls. The clinical features of the disease were not significantly influenced by different genotypes. In conclusion, our study suggests that the 3092 T-->C polymorphism of the Clock gene is unlikely to play an important role in cluster headache.