Study Report
Basic Info
Reference |
Friedel S, 200515457498
|
Citation |
Friedel S., Horro F. F., Wermter A. K., Geller F., Dempfle A., Reichwald K., Smidt J., Bronner G., Konrad K., Herpertz-Dahlmann B., Warnke A., Hemminger U., Linder M., Kiefl H., Goldschmidt H. P., Siegfried W., Remschmidt H., Hinney A. and Hebebrand J. (2005) "Mutation screen of the brain derived neurotrophic factor gene (BDNF): identification of several genetic variants and association studies in patients with obesity, eating disorders, and attention-deficit/hyperactivity disorder." Am J Med Genet B Neuropsychiatr Genet, 132B(1): 96-9.
|
Study Design |
case-control |
Study Type |
Candidate-gene association study |
Sample Size |
88 patients with ADHD, and 96 normal weight controls |
Predominant Ethnicity |
Caucasian |
Population |
Germany |
Age Group |
Children/Adolescents
|
Detail Info
Summary |
A mutation screen (SSCP and DHPLC) of the translated region of BDNF in 183 extremely obese children and adolescents and 187 underweight students was performed. Additionally, they genotyped two common polymorphisms (rs6265: p.V66M; c.-46C>T) in 118 patients with anorexia nervosa, 80 patients with bulimia nervosa, 88 patients with ADHD, and 96 normal weight controls. Three rare variants (c.5C>T: p.T2I; c.273G>A; c.*137A>G) and the known polymorphism (p.V66M) were identified. A role of the I2 allele in the etiology of obesity cannot be excluded. They found no association between p.V66M or the additionally genotyped variant c.-46C>T and obesity, ADHD or eating disorders. |
Total Sample |
They analyzed two common polymorphisms (V66M in the 5' pro-region; SNP c.-46C>T in one of the 5'UTR exons, Kunugi et al., 2001) in the initial study groups and additionally in 118 patients with AN, 80 patients with BN, 88 patients with ADHD, and 96 normal weight controls. |
Sample Collection |
For association studies, they used the initial screening-sample and samples of patients with ADHD, AN, BN, and normal weight controls (see the online Table II at http://www.interscience. wiley.com/jpages/0148-7299:1/suppmat/index.html). |
Diagnosis Description |
Patients with ED or with ADHD fulfilled DSM-IV criteria [APA, 1994]. Written informed consent was given by all participants and, in the case of minors, their parents. This study was approved by the Ethics Committee of the University of Marburg. |
Technique |
PCR products of all SNPs were run on ethidium bromide-stained 2.5% agarose gels. Positive controls for the variant alleles were run on each gel. For validity of the genotypes, allele determinations were rated independently by at least two experienced individuals. Discrepancies were resolved unambiguously either by reaching consensus or by retyping (see the online Table IV at http://www.interscience.wiley.com/jpages/ 0148-7299:1/suppmat/index.html). |
Analysis Method |
Differences in genotype frequencies were investigated using the Cochran-Armitage trend test. Pearson's X2-tests were carried out to investigate differences in allele frequencies. They did not correct for the multiple tests they performed for the different groups at the two loci. Therefore, all reported P values are nominal. |
Result Description |
Association studies revealed no significant differences in genotype or allele distributions between extremely obese children and adolescents and underweight controls, as well as between AN,ADHD, and normal weight students; all nominal P values were>0.2. |
SNPs reported by this study (count: 1)
SNP |
Allele Change |
Risk Allele |
Statistical Values |
Author Comments |
Result of Statistical Analysis |
rs6265 |
G/A |
|
genotypic Cochran-Armitage trend test P-value>0.2 |
no significant difference was observed
no significant difference was observed
|
Non-significant
|
Other variant reported by this study (count: 1)
Variant Name |
Allele Change |
Risk Allele |
Statistical Values |
Author Comments |
Result of Statistical Analysis |
BDNF C270T |
C/T |
|
genotypic Cochran-Armitage trend test P-value>0.2
genotypic Cochran-Armitage trend test P-value>0.2
|
no significant difference was observed |
Non-significant
|
Genes reported by this study (count: 1)
Gene |
Statistical Values/Author Comments |
Result of Statistical Analysis |
BDNF |
revealed no significant differences in genotype or allele di......
revealed no significant differences in genotype or allele distributions
More...
|
Non-significant
|