Objective: To investigate associations between brain-derived neurotrophic factor (BDNF) gene polymorphisms and regional frontal cortical thickness and volume in patients with schizophrenia and healthy control participants.
Methods: BDNF genotyping was performed using polymerase chain reaction and pyrosequencing techniques in 96 patients with schizophrenia or schizoaffective disorder and 104 healthy control participants. Cortical morphology was analyzed by processing magnetic resonance brain images with the FreeSurfer software package. General linear model analysis was used to study associations between BDNF variants and cortical thickness in patients and controls, respectively. Regional frontal cortical volumes were defined from automatic cortical parcellations.
Results: For patients with schizophrenia, there was an association between the BDNF -633 T/A polymorphism and thickness and volume of distinct subregions of the prefrontal cortex. Data indicated trends toward genotypic associations between the BDNF 270 C/T and 11757 G/C polymorphisms and the volume of specific frontal lobe regions in patients with schizophrenia. Among controls, there were no significant associations between BDNF polymorphisms and cortical thickness. Trends toward genotypic associations between BDNF polymorphisms and volumes of some frontal lobe regions for control participants were observed, although these differences did not reach statistical significance.
Conclusion: Polymorphisms in the BDNF gene may be associated with variation in frontal lobe morphology. Associations seem to be stronger in patients with schizophrenia than in healthy controls.