title: A genome-wide association study of seasonal pattern mania identifies NF1A as a possible susceptibility gene for bipolar disorder.
abstract: OBJECTIVE
  The use of subphenotypes may be an effective approach for genetic studies of complex diseases. Manic episodes with a seasonal pattern may distinguish phenotypic subgroups of bipolar subjects that may also differ genetically.
  
  
  METHODS
  We have performed a genome-wide association study using GAIN genotype data from the Bipolar Genome Study (BiGS) and bipolar subjects that were categorized as having either seasonal or non-seasonal patterned manic episodes.
  
  
  RESULTS
  A bipolar case-only analysis identified three genomic regions that differed between seasonal and non-seasonal patterned manic episodes of bipolar subjects. The most significant association was for rs41350144, which lies within an intron of NF1A gene on 1p31 (P=3.08×10(-7), OR=2.27). Haplotype construction using flanking three SNPs (rs41453448, rs1125777, and rs12568010) spanning 7549bp showed a more significant association (P=2.12×10(-7), OR=0.4).
  
  
  CONCLUSIONS
  These data suggest that genetic variants in the NF1A gene region may predispose to seasonal patterned of mania in bipolar disorder.
authors.affiliation: Department of Psychiatry, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Heon-Jeong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Hyun Goo
authors.initials: HG
authors.lastname: Woo
authors.forename: Tiffany A
authors.initials: TA
authors.lastname: Greenwood
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Kripke
authors.forename: John R
authors.initials: JR
authors.lastname: Kelsoe
mesh_terms: D001714:Bipolar Disorder / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007438:Introns / Q000235:genetics; D051839:NFI Transcription Factors / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012621:Seasons
chemical_list: D051839:NFI Transcription Factors; C497592:NFIA protein, human