Novel Potential Risk Loci for Migraine in the Portuguese Population.

Common forms of migraine are complex disorders characterized by significant clinical diversity. Their genetic basis has been extensively studied but remains unclear. This study represents the first pilot genome-wide association study (GWAS) integrating a polygenic risk score (PRS) in the Portuguese population, designed to identify migraine susceptibility loci through a case-control study and unravel population-specific variants. Genotyping data was acquired with Applied Biosystems Axiom™ PMDA array, producing 12,035,248 single-nucleotide polymorphisms (SNPs) post-imputation, providing a comprehensive scope for GWAS analysis. PRS models were created and tested using a k-folds cross-validation framework and the optimal significance threshold was assessed. We detected 12 potential risk loci corresponding to 12 lead SNPs (RP11-204N11.2, CTA-481E9.4/CTA-481E9.3, RAP1A, TIGD4, CADPS2, RP11-46E17.6, RP4-569D19.5, RP11-398K14.1, PCBP1-AS1, TCF15, IL6R and UNC13A). The top three variants (RP11-204N11.2, CTA-481E9.4/CTA-481E9.3 and RAP1A) were also supported by the PRS model. We highlight that several variants present putative biological relevance to migraine pathophysiology, reinforcing the importance of neurotransmitter release, synaptic transmission and the involvement of vascular components in migraine pathophysiology.