Evidence of association between brain-derived neurotrophic factor gene and bipolar disorder.
OBJECTIVE
Brain-derived neurotrophic factor (BDNF) plays an important role in the survival, differentiation, and outgrowth of select peripheral and central neurons throughout adulthood. Growing evidence suggests that BDNF is involved in the pathophysiology of mood disorders.


METHODS
Ten single nucleotide polymorphisms (SNPs) across the BDNF gene were genotyped in a sample of 1749 Caucasian Americans from 250 multiplex bipolar families. Family-based association analysis was used with three hierarchical bipolar disorder models to test for an association between SNPs in BDNF and the risk of bipolar disorder. In addition, an exploratory analysis was performed to test for an association of the SNPs in BDNF and the phenotypes of rapid cycling and episode frequency.


RESULTS
Evidence of association (P<0.05) was found with several of the SNPs using multiple models of bipolar disorder; one of these SNPs also showed evidence of association (P<0.05) with rapid cycling.


CONCLUSIONS
These results provide further evidence that variation in BDNF affects the risk for bipolar disorder.
Liu
Lixiang
L
Indiana University, Indianapolis, Indiana 46202-3002, USA.
Foroud
Tatiana
T
Xuei
Xiaoling
X
Berrettini
Wade
W
Byerley
William
W
Coryell
William
W
El-Mallakh
Rif
R
Gershon
Elliot S
ES
Kelsoe
John R
JR
Lawson
William B
WB
MacKinnon
Dean F
DF
McInnis
Melvin
M
McMahon
Francis J
FJ
Murphy
Dennis L
DL
Rice
John
J
Scheftner
William
W
Zandi
Peter P
PP
Lohoff
Falk W
FW
Niculescu
Alexander B
AB
Meyer
Eric T
ET
Edenberg
Howard J
HJ
Nurnberger
John I
JI
D001714:Bipolar Disorder / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D015810:Linkage Disequilibrium; D020641:Polymorphism, Single Nucleotide
D019208:Brain-Derived Neurotrophic Factor