“…Twelve case-control studies investigated the role of common genetic polymorphisms as risk factors for MOH susceptibility (22,(25)(26)(27)(28)(29)(31)(32)(33)(34)36,37). Overall, 50 polymorphisms were analysed in 33 genes related to serotoninergic transmission (SLC6A4, 5HT1A, 5HT2A, 5HT1B, GNB3, 5HT6, TPH2), dopaminergic transmission (SLC6A3, COMT, DBH, DRD2 and DRD4), drug dependence (ACE, OPRM1, BDNF, EEAT2), metabolic pathways (CYP1A2, MAOA, MTHFR), oxidative stress (eNOS, nNOS, GTPCH, GSTP1, GSTM1, GSTT1, SOD, CAT, PON, CYBA), CGRP pathway (CALCA, RAMP1), and genes postulated to be relevant for migraine pathophysiology (ESR1, TNF-b).…”