title: Case-control association study of 65 candidate genes revealed a possible association of a SNP of HTR5A to be a factor susceptible to bipolar disease in Bulgarian population.
abstract: BACKGROUND
  Bipolar affective disorder (BAD) is a psychiatric illness characterized by episodes of mania and depression. Although the etiology is not clear, epidemiological studies suggest it is a result of an interaction of genetic and environmental factors. Despite of enormous efforts and abundant studies conducted, none has yet been identified definitively a gene susceptible to bipolar disorder.
  
  
  METHODS
  Ninety-four Bulgarian patients diagnosed with bipolar disorder and 184 Bulgarian healthy individuals, were used for genotyping of 191 single nucleotide polymorphisms (SNPs) by TaqMan and/or Invader assays. Seventeen SNPs that revealed P value less than 0.05 in the first screening were genotyped using an additional independent set of samples, consisting of 78 BAD cases and 372 controls.
  
  
  RESULTS
  After applying the Bonferonni correction on genotyping results of 172 cases and 556 controls, only one SNP, rs1800883, in the HTR5A gene revealed a significant level of P value (P=0.000097; odds ratio=1.80 (95%CI, 1.27-2.54); corrected P=0.017).
  
  
  CONCLUSIONS
  Our findings suggest that HTR5A gene could play an important role in the pathogenesis of bipolar disorder in our population. However these findings should be viewed with caution and replication studies in other populations are necessary in support of these findings.
authors.affiliation: Laboratory for International Alliance, RIKEN Center for Genomic Medicine, Tsurumi-ku, Yokohama, Japan.
authors.forename: Adelina
authors.initials: A
authors.lastname: Yosifova
authors.forename: Taisei
authors.initials: T
authors.lastname: Mushiroda
authors.forename: Drozdstoi
authors.initials: D
authors.lastname: Stoianov
authors.forename: Radoslava
authors.initials: R
authors.lastname: Vazharova
authors.forename: Ivanka
authors.initials: I
authors.lastname: Dimova
authors.forename: Sena
authors.initials: S
authors.lastname: Karachanak
authors.forename: Irina
authors.initials: I
authors.lastname: Zaharieva
authors.forename: Vihra
authors.initials: V
authors.lastname: Milanova
authors.forename: Nadejda
authors.initials: N
authors.lastname: Madjirova
authors.forename: Ivan
authors.initials: I
authors.lastname: Gerdjikov
authors.forename: Todor
authors.initials: T
authors.lastname: Tolev
authors.forename: Stoyanka
authors.initials: S
authors.lastname: Velkova
authors.forename: George
authors.initials: G
authors.lastname: Kirov
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Owen
authors.forename: Michael C
authors.initials: MC
authors.lastname: O'Donovan
authors.forename: Draga
authors.initials: D
authors.lastname: Toncheva
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nakamura