Linkage disequilibrium of the brain-derived neurotrophic factor Val66Met polymorphism in children with a prepubertal and early adolescent bipolar disorder phenotype.
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.
Geller
Barbara
B
Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA. gellerb@medicine.wustl.edu
Badner
Judith A
JA
Tillman
Rebecca
R
Christian
Susan L
SL
Bolhofner
Kristine
K
Cook
Edwin H
EH
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*
D019208:Brain-Derived Neurotrophic Factor