title: Genetic polymorphisms and the adequacy of brain stimulation: state of the art.
abstract: Heterogeneity of therapeutic response to brain stimulation techniques has inspired scientists to uncover the secrets to success or failure of these projects. Genetic polymorphisms are one of the major causes of this heterogeneity.
  
  
  
  More than twenty genetic variants within more than ten genes (e.g. BDNF, COMT, DRD2, TRPV1, 5-HT1A, 5-HHT, P2RX7, VEGF, TPH1, TPH2, ACE, APOE, GNB3, NET, NMDA receptors, and RGS4) have been investigated, among which the BDNF gene and its polymorphism, Val66Met, is the best documented variant. We review the genotypic combinations, which are reported to interact with the work of brain stimulation, of which the DRD2 C957T polymorphism is the most prominent type. Finally, implications of transcranial magnetic stimulation in deciphering the interaction between genetic background (e.g. SCN1A and 5-HTT) and drugs (e.g. carbamazepine and citalopram) at the cortical excitability level is explained. Expert commentary: Studies are ongoing to find missing factors responsible for heterogeneity of response to brain stimulation techniques. Further knowledge about genetic factors affecting the therapeutic response to brain stimulation techniques might provide helpful guidelines for choosing ideal candidates for treatment.
authors.affiliation: a Research Center for Immunodeficiencies, Children's Medical Center , Tehran University of Medical Sciences , Tehran , Iran.|b NeuroImmunology Research Association (NIRA) , Universal Scientific Education and Research Network (USERN) , Tehran , Iran.
authors.forename: Amene
authors.initials: A
authors.lastname: Saghazadeh
authors.affiliation: c Department of Radiology, Massachusetts General Hospital , Harvard Medical School , Boston , MA , USA.|d Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA) , Universal Scientific Education and Research Network (USERN) , Boston , MA , USA.
authors.forename: Shadi A
authors.initials: SA
authors.lastname: Esfahani
authors.affiliation: a Research Center for Immunodeficiencies, Children's Medical Center , Tehran University of Medical Sciences , Tehran , Iran.|e Department of Immunology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.|f Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA) , Universal Scientific Education and Research Network (USERN) , Tehran , Iran.
authors.forename: Nima
authors.initials: N
authors.lastname: Rezaei
mesh_terms: D001921:Brain / Q000378:metabolism / Q000503:physiopathology; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D050781:Transcranial Magnetic Stimulation; D016896:Treatment Outcome
chemical_list: D019208:Brain-Derived Neurotrophic Factor
keywords: Single nucleotide polymorphisms; brain stimulation; pharmacogenetics