title: Linkage disequilibrium of the brain-derived neurotrophic factor Val66Met polymorphism in children with a prepubertal and early adolescent bipolar disorder phenotype.
abstract: OBJECTIVE
  Transmission of the brain-derived neurotrophic factor (BDNF) Val66 allele in children with a prepubertal and early adolescent bipolar disorder phenotype was examined.
  
  
  METHODS
  The prepubertal and early adolescent bipolar disorder phenotype was defined as current DSM-IV bipolar I disorder (manic or mixed phase) with at least one cardinal mania criterion (i.e., euphoria and/or grandiosity) to ensure differentiation from attention deficit hyperactivity disorder. Probands (mean age=10.7 years, SD=2.7) were obtained by consecutive new case ascertainment from designated pediatric and psychiatric venues. Parents and probands were interviewed separately by research nurses who were blind to the probands' diagnoses. Genotyping was done with TaqMan Assay-on-Demand. Analysis was done with the Family Based Association Test program.
  
  
  RESULTS
  There were 53 complete, independent trios. The BDNF Val66 allele was preferentially transmitted (Family Based Association Test: chi(2)=6.0, df=1, p=0.014).
  
  
  CONCLUSIONS
  This finding in child bipolar disorder is consistent with data for adults with bipolar disorder that show preferential transmission of the Val66 allele.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA. gellerb@medicine.wustl.edu
authors.forename: Barbara
authors.initials: B
authors.lastname: Geller
authors.forename: Judith A
authors.initials: JA
authors.lastname: Badner
authors.forename: Rebecca
authors.initials: R
authors.lastname: Tillman
authors.forename: Susan L
authors.initials: SL
authors.lastname: Christian
authors.forename: Kristine
authors.initials: K
authors.lastname: Bolhofner
authors.forename: Edwin H
authors.initials: EH
authors.lastname: Cook
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D001714:Bipolar Disorder / Q000453:epidemiology / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics*; D008137:Longitudinal Studies; D010641:Phenotype; D011110:Polymorphism, Genetic; D011627:Puberty / Q000235:genetics*
chemical_list: D019208:Brain-Derived Neurotrophic Factor