Association of dopamine D2 receptor (DRD2) C939T and a lack of association of Tumor Factor-β (TNF-β) +A252G polymorphisms with susceptibility to Migraine in A Northern Iranian population

Two single nucleotide polymorphisms (SNPs) in TNF and DRD2 genes (TNF-β +A252G and DRD2 C939T) were genotyped by PCR restriction fragment length polymorphism (PCR-RFLP). The forward and reverse primer sequences for the two SNPs are listed in table 1. Finally, to ensure the reliability of the PCR–RFLP results, the PCR products were sequenced by the Sanger sequencing method, and sequences of the PCR products were analyzed by the Codon Code Aligner software.