title: CHRNA7 haplotypes are associated with impaired attention in euthymic bipolar disorder.
abstract: BACKGROUND
  Bipolar disorder (BD) patients show a deficit in sustained attention during euthymic periods. This deficit may be relevant for genetic studies in these patients. The α7 cholinergic receptor plays an important role in attentional deficit in humans and animal models. Moreover, there is evidence suggesting the role of the alpha 7 nicotinic cholinergic receptor subunit gene (CHRNA7) in BD susceptibility. The aim of the present study was to investigate the impact of CHRNA7 in sustained attention performance.
  
  
  METHODS
  We studied the association of a promoter variant (-86C/T) and three intronic polymorphisms, rs883473, rs6494223 and rs904952, in the non-duplicated region of CHRNA7 with sustained attention in 143 euthymic BD patients (based on DSM-IV criteria) and 101 healthy subjects. Sustained attention was assessed by the degraded stimulus (DS-CPT) version of Continuous Performance Test. Age, gender, years of education and IQ (WAIS vocabulary subtest) were controlled in the analyses as potential confounders.
  
  
  RESULTS
  Several candidate polymorphisms showed significant associations with different measures of the neuropsychological task for bipolar group. The CTCT haplotype was associated with an improvement in the attentional task performance in the BD group (p ≤ 0.025). On the other hand, different low frequency haplotypes showed influence in bipolar attentional performance (p ≤ 0.026).
  
  
  CONCLUSIONS
  A replication study using larger samples may be required for conclusive results.
  
  
  CONCLUSIONS
  Our results point toward a slight association of CHRNA7 genotypes and haplotypes with sustained attention performance in euthymic patients with BD.
authors.affiliation: Laboratory of Psychoneuroendocrinology and Molecular Genetics, Biomedical Research Foundation, Clínico San Carlos Hospital, Madrid, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Ancín
authors.forename: J A
authors.initials: JA
authors.lastname: Cabranes
authors.forename: J L
authors.initials: JL
authors.lastname: Santos
authors.forename: E
authors.initials: E
authors.lastname: Sánchez-Morla
authors.forename: B
authors.initials: B
authors.lastname: Vázquez-Álvarez
authors.forename: L
authors.initials: L
authors.lastname: Rodríguez-Moya
authors.forename: A
authors.initials: A
authors.lastname: Pousada-Casal
authors.forename: C
authors.initials: C
authors.lastname: Fernández
authors.forename: A
authors.initials: A
authors.lastname: Aparicio
authors.forename: A
authors.initials: A
authors.lastname: Barabash
mesh_terms: D000328:Adult; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics; D001714:Bipolar Disorder / Q000235:genetics* / Q000503:physiopathology* / Q000523:psychology; D016022:Case-Control Studies; D003527:Cyclothymic Disorder / Q000235:genetics; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011978:Receptors, Nicotinic / Q000235:genetics*; D064569:alpha7 Nicotinic Acetylcholine Receptor
chemical_list: C579167:Chrna7 protein, human; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor