For instance, genes related to vascular modifications and cardiovascular diseases, e.g. SNPs of the gene OMIM encoding the angiotensin converting enzyme (ACE) or SNPs of the methylenetetrahydrofolate reductase (MTHFR) genetic variants have been implicated in the susceptibility to migraine and aura and in the frequency of migraine attacks. Here, MTHFR is linked to migraine disorder.