title: Polymorphism in the promoter of the gene for the serotonin transporter affects the age of onset of major depressive disorder in the Japanese population.
abstract: OBJECTIVE
  Recent research has suggested that a functional polymorphism in the promoter region of the serotonin transporter gene (serotonin transporter-linked polymorphic region, 5HTTLPR) may be implicated in gene-environment interactions leading to major depressive disorder (MDD).
  
  
  METHODS
  Our study examined the association between 5HTTLPR and clinical variables of MDD in the Japanese population. We genotyped 5HTTLPR in 216 patients with MDD and 213 age- and sex-matched controls.
  
  
  RESULTS
  The genotype distributions and allele frequencies were similar in the patients and controls. When the relationships between the polymorphism and several clinical variables (i.e., age of onset, number of episodes, presence of psychotic features, suicidal behavior, and family history) were examined, the dose of the long (l) allele had significant effects on the age of onset.
  
  
  CONCLUSIONS
  These results suggest that 5HTTLPR may not be entirely related to the development of MDD but may be related to the age of onset of MDD, which may be due to gene-environment interactions in the Japanese population.
  
  
  CONCLUSIONS
  Because of the low frequencies of psychotic features and suicidal behavior, our results must be treated with caution until they are replicated in larger numbers of Japanese samples. MDD patients did not undergo a structured interview. Clinical information from the medical records may have not been complete.
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
authors.forename: Shin-ya
authors.initials: SY
authors.lastname: Watanabe
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan. Electronic address: igajunichi@hotmail.com.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Iga
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
authors.forename: Shusuke
authors.initials: S
authors.lastname: Numata
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Umehara
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Nishi
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kinoshita
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Inoshita
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ohmori
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics*; D003865:Major Depressive Disorder / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D059647:Gene-Environment Interaction; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*
chemical_list: D009419:Nerve Tissue Proteins; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins
keywords: Age of onset; Gene association; Major depressive disorder; Promoter; Serotonin transporter