Evaluation of GABBR2 gene polymorphisms rs230416 and rs230429 in migraine with aura: A case-control study in a Turkish population

Objectives: This study aimed to investigate the association between two single-nucleotide polymorphisms, rs230416 and rs230429, in the GABBR2 (gamma-aminobutyric acid type B receptor subunit 2) gene and susceptibility to migraine with aura in a Turkish cohort. Patients and methods: In this case-control study, a total of 100 patients (15 males, 85 females; mean age: 33.68 ± 12.16 years; range, 18 to 55 years) with migraine diagnosed according to the International Classification of Headache Disorders criteria and 100 age-and sex-matched healthy controls (25 males, 75 females; mean age: 33.68 ± 12.16 years; range, 18 to 55 years) were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method between January 2018 and June 2013. Genotype and allele frequencies were compared between groups. The Hardy–Weinberg equilibrium, the chi-square test, and Fisher’s exact test were used for statistical analysis (p < 0.05). Power analysis and genetic equilibrium testing were also performed. Results: For rs230416, genotype distributions were 10% GG, 30% AG, and 60% AA in migraineurs, and 5% GG, 25% AG, and 70% AA in controls (p = 0.15). Minor allele (G) frequencies were 25% in cases and 17.5% in controls (p = 0.07). For rs230429, distributions were 10% TT, 38% CT, and 52% CC in patients, and 8% TT, 34% CT, and 58% CC in controls (p = 0.42), with T allele frequencies of 29% and 25%, respectively (p = 0.45). All genotype distributions conformed to the Hardy-Weinberg equilibrium. Conclusion: Although this study did not find a significant association between rs230416 or rs230429 and migraine susceptibility, the findings contribute to the growing literature supporting a minor but biologically relevant role of gamma-aminobutyric acidmediated pathways in migraine. Future studies with larger, ethnically diverse cohorts and integrative omics approaches are warranted to clarify the functional impact of GABBR2 variants.