Association study of theta EEG asymmetry and brain-derived neurotrophic factor gene variants in childhood-onset mood disorder.
BACKGROUND
Childhood-onset mood disorders (COMD) include various serious, disabling psychiatric conditions that are heterogeneous in presentation and etiology. Because intermediate phenotypes may help to identify genetic contributors to COMD, we tested for an association between variants in the brain-derived neurotrophic factor (BDNF) gene and theta EEG asymmetry, both of which have been independently implicated in affective disorders.


METHODS
Theta EEG asymmetry measures were calculated for a total of 191 individuals with COMD and 93 controls, who were also genotyped at seven BDNF single-nucleotide polymorphism (SNPs), two intergenic flanking SNPs, and one SNP in the lin-7 homolog C (Caenorhabditis elegans) (LIN7C) gene.


RESULTS
Adjusting for sex and ethnicity in linear models of asymmetry scores at ten brain regions, significant genotype and genotype-by-ethnicity interactions were observed for marker Val66Met in two parietal (P3/4 and P7/8) regions in the depressed group only.


CONCLUSIONS
Our results suggest that the functional Val66Met polymorphism affects theta EEG asymmetry in parietal brain regions specifically in individuals with COMD.
Centre for Addiction and Mental Health, University of Toronto, 250 College St., Toronto, ON, Canada.
Natalie L
NL
Bulgin
John S
JS
Strauss
Nicole A
NA
King
Sajid A
SA
Shaikh
Charles J
CJ
George
Nathan A
NA
Fox
Cathy L
CL
Barr
Maria
M
Kovacs
James L
JL
Kennedy
D000328:Adult; D017668:Age of Onset; D019943:Amino Acid Substitution / Q000235:genetics; D001921:Brain / Q000378:metabolism / Q000503:physiopathology*; D001931:Brain Mapping; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D004252:DNA Mutational Analysis; D004569:Electroencephalography; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D019964:Mood Disorders / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology*; D010296:Parietal Lobe / Q000378:metabolism / Q000503:physiopathology; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D013826:Theta Rhythm; D055815:Young Adult
D019208:Brain-Derived Neurotrophic Factor; D005819:Genetic Markers