title: Association between serotonin 4 receptor gene polymorphisms and bipolar disorder in Japanese case-control samples and the NIMH Genetics Initiative Bipolar Pedigrees.
abstract: Possible irregularities in serotonergic neurotransmission have been suggested as causes of a variety of neuropsychiatric diseases. We performed mutation and association analyses of the HTR4 gene, on 5q32, encoding the serotonin 4 receptor in mood disorders and schizophrenia. Mutation analysis was performed on the HTR4 exons and exon/intron boundaries in 48 Japanese patients with mood disorders and 48 patients with schizophrenia. Eight polymorphisms and four rare variants were identified. Of these, four polymorphisms at or in close proximity to exon d, g.83097C/T (HTR4-SVR (splice variant region) SNP1), g.83159G/A (HTR4-SVRSNP2), g.83164 (T)9-10 (HTR4-SVRSNP3), and g.83198A/G (HTR4-SVRSNP4), showed significant association with bipolar disorder with odds ratios of 1.5 to 2. These polymorphisms were in linkage disequilibrium, and only three common haplotypes were observed. One of the haplotypes showed significant association with bipolar disorder (P = 0.002). The genotypic and haplotypic associations with bipolar disorder were confirmed by transmission disequilibrium test in the NIMH Genetics Initiative Bipolar Pedigrees with ratios of transmitted to not transmitted alleles of 1.5 to 2.0 (P = 0.01). The same haplotype that showed association with bipolar disorder was suggested to be associated with schizophrenia in the case-control analysis (P = 0.003) but was not confirmed when Japanese schizophrenia families were tested. The polymorphisms associated with mood disorder were located within the region that encodes the divergent C-terminal tails of the 5-HT(4) receptor. These findings suggest that genomic variations in the HTR4 gene may confer susceptibility to mood disorder.
authors.affiliation: Department of Medical Genetics, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ohtsuki
authors.forename: H
authors.initials: H
authors.lastname: Ishiguro
authors.forename: S D
authors.initials: SD
authors.lastname: Detera-Wadleigh
authors.forename: T
authors.initials: T
authors.lastname: Toyota
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
authors.forename: K
authors.initials: K
authors.lastname: Yamada
authors.forename: K
authors.initials: K
authors.lastname: Yoshitsugu
authors.forename: E
authors.initials: E
authors.lastname: Hattori
authors.forename: T
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: T
authors.initials: T
authors.lastname: Arinami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001714:Bipolar Disorder / Q000453:epidemiology* / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D006239:Haplotypes; D006801:Humans; D007564:Japan; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011110:Polymorphism, Genetic; D011985:Receptors, Serotonin / Q000235:genetics*; D044422:Receptors, Serotonin, 5-HT4; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology / Q000235:genetics
chemical_list: D011985:Receptors, Serotonin; D044422:Receptors, Serotonin, 5-HT4