An association study in an Italian population of 256 migraine patients and 237 healthy age-, sex-, and ethnicity-matched controls showed that patients with the H63D GG (D63D) genotype presented significantly later age of disease onset and increased frequency of migraine attacks, concluding that the HFE H63D variant may be a modifying genetic factor in migraine (Rainero et al. 2007). Here, HFE is linked to migraine disorder.