title: Association between HTR2C gene variants and suicidal behaviour: a protocol for the systematic review and meta-analysis of genetic studies.
abstract: BACKGROUND
  Suicide is an important public health problem and one of the most common causes of death throughout the world. Suicidal behaviour is complex, and its causes are multifactorial. Case-control studies have reported an association between an alteration of the serotonin system and suicidal behaviour. Recently, it has been suggested that the 5-HTRC2 serotonin receptor gene is involved in the pathogenesis of suicidal behaviour.
  
  
  METHODS
  To evaluate the role of the 5-HTR2C gene in suicidal behaviour, we will perform a systematic review and a meta-analysis of worldwide reports that have investigated the association between the serotonin system and suicidal behaviour. This analysis will be reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Studies deemed fit for inclusion in the systematic review will be scored for methodological quality using the Newcastle-Ottawa Assessment Scale (NOS). The inclusion criteria will be to present independent data, to be case-control studies and to be published in journal peer reviews. To generate more accurate analyses, we will grade the reports using the GRADES scale procedures.
  
  
  BACKGROUND
  This study will describe the association between the HTR2C gene and suicidal behaviour. The results will be reported in a peer-reviewed publication and in scientific presentations in Mexico and throughout the world.
  
  
  BACKGROUND
  PROSPERO CRD42014009213.
authors.affiliation: División Académica de Ciencias de la Salud, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, México.
authors.forename: González-Castro
authors.initials: GC
authors.lastname: Thelma Beatriz
authors.affiliation: División Académica de Ciencias de la Salud, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, México.
authors.forename: Juárez-Rojop
authors.initials: JR
authors.lastname: Isela
authors.affiliation: Servicios de Atención Psiquiátrica (SAP), Secretaría de Salud, Instituto Nacional de Medicina Genómica (INMEGEN), México, Distrito Federal, México.
authors.forename: Genis
authors.initials: G
authors.lastname: Alma
authors.affiliation: Secretaria de Salud, Hospital General de Yajalón, Yajalón, Chiapas, México.
authors.forename: López-Narváez
authors.initials: LN
authors.lastname: María Lilia
authors.affiliation: División Académica Multidisciplinaria de Comalcalco, Universidad Juárez Autónoma de Tabasco, Comalcalco, Tabasco, México.
authors.forename: Tovilla-Zárate
authors.initials: TZ
authors.lastname: Carlos Alfonso
mesh_terms: D056726:Genetic Association Studies; D014644:Genetic Variation; D006801:Humans; D015201:Meta-Analysis as Topic; D044405:Receptor, Serotonin, 5-HT2C / Q000235:genetics*; D013405:Suicide; D000078202:Systematic Reviews as Topic
chemical_list: D044405:Receptor, Serotonin, 5-HT2C
keywords: PSYCHIATRY; STATISTICS & RESEARCH METHODS