A replication study of a GWAS finding in migraine does not identify association in a Spanish case-control sample

Background: Migraine is a prevalent neurological disorder with a complex genetic background characterized by recurrent episodes of headache. The disease is subclassified into migraine with aura (MA) and migraine without aura (MO). Many association studies have been performed to date to identify genetic risk variants for common migraine, most of them focusing on selected candidate genes, with variable and often inconsistent results. Recently, a clinic-based genome-wide association study for migraine reported a functionally relevant risk variant (SNP rs1835740), involved in glutamate homeostasis, which showed a significant association with MA. We aimed to replicate this finding in a clinic-based study of a Spanish cohort with MA and MO patients. Methods: We genotyped SNP rs1835740 in a Spanish sample of 1521 patients and 1379 screened controls and performed a case-control association study. Conclusion: No association was found between the assayed SNP and any of the clinical groups considered.