title: Association of the serotonin transporter polymorphism and obsessive-compulsive disorder: systematic review.
abstract: We investigated the association between the long (l) and short (s) alleles of the serotonin transporter polymorphism (5-HTTLPR) in the promoter region of the SLC6A4 gene and obsessive-compulsive disorder (OCD) using meta-analysis to combine all published data from case-control and family based association studies (2,283 cases). In stratified meta-analysis we investigated whether age of sample (child and adult), ethnicity (Caucasian and Asian) and study design (case-control and family-based association studies) moderated any association. In the overall meta-analysis we found no evidence of association between genetic variation at the 5-HTTLPR locus and OCD. We did find significant heterogeneity between studies. In the stratified meta-analyses, we demonstrated a significant association between the l-allele and OCD in family-based association studies and in studies involving children and Caucasians. Our meta-analysis suggests the possibility that the l-allele may be associated with OCD in specific OCD subgroups such as childhood-onset OCD and in Caucasians. Further meta-analyses based on individual patient data would be helpful in determining whether age of OCD onset, gender and the presence of comorbid illness (e.g., tics) moderates the relationship between 5-HTTLPR and OCD.
authors.affiliation: Yale Child Study Center, Yale University School of Medicine, New Haven, Connecticut 06520, USA. michael.bloch@yale.edu <michael.bloch@yale.edu>
authors.forename: Michael H
authors.initials: MH
authors.lastname: Bloch
authors.forename: Angeli
authors.initials: A
authors.lastname: Landeros-Weisenberger
authors.forename: Srijan
authors.initials: S
authors.lastname: Sen
authors.forename: Philip
authors.initials: P
authors.lastname: Dombrowski
authors.forename: Ben
authors.initials: B
authors.lastname: Kelmendi
authors.forename: Vladimir
authors.initials: V
authors.lastname: Coric
authors.forename: Christopher
authors.initials: C
authors.lastname: Pittenger
authors.forename: James F
authors.initials: JF
authors.lastname: Leckman
mesh_terms: D016022:Case-Control Studies; D005787:Gene Frequency; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D006801:Humans; D009771:Obsessive-Compulsive Disorder / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins