ABSTRACT
We investigated the association between a brain-derived neurotrophic factor (BDNF) gene polymorphism and clinical features in a sample of patients with obsessive-compulsive disorder (OCD). A total of 100 patients diagnosed with OCD according to the Diagnostic and Statistical Manual IV criteria and 110 control subjects were included in this study. The distribution of a single nucleotide polymorphism rs2883187 was compared in OCD patients and normal controls. Clinical features were compared between the subgroups of OCD patients with different genotypes. There was no significant difference for the allele frequencies and genotype distributions between the OCD and control groups. The Hamilton Anxiety Rating Scale, Yale-Brown Obsessive Compulsive Scale obsession and total scores were found to be higher in patients with the CC genotype than in the patients who are homozygous for the T allele. The rates of OCD in first-degree relatives of OCD patients who were homozygous for the C allele were significantly higher, compared to those with CT and TT genotypes. Our results indicate that the CC genotype may be associated with the severity and increased familial loading of OCD. Further investigation based on larger populations is needed to reveal the full association of the BDNF polymorphism with OCD.
Subject(s)
Brain-Derived Neurotrophic Factor/genetics , Gene Expression Regulation , Obsessive-Compulsive Disorder/diagnosis , Obsessive-Compulsive Disorder/genetics , Phenotype , Polymorphism, Single Nucleotide/genetics , Adult , Female , Humans , Male , Obsessive-Compulsive Disorder/psychology , Young AdultABSTRACT
This study investigated the association between the catechol-O-methyl transferase (COMT) Val158Met polymorphism and executive functions in 101 patients with obsessive-compulsive disorder (OCD) and 100 healthy-control subjects (HS). Results showed that there was no significant difference for the genotype distributions between the OCD and HS groups. OCD-Met carrier subgroup's TMT B-A difference and lexical fluency scores were found to be significantly poorer than both HS subgroups. These findings suggest that lower activity of COMT associated with the Met allele, leading to higher levels of dopamine in the prefrontal cortex, lead to poorer executive function in OCD.
Subject(s)
Catechol O-Methyltransferase/genetics , Cognition Disorders/etiology , Executive Function/physiology , Obsessive-Compulsive Disorder/complications , Obsessive-Compulsive Disorder/genetics , Polymorphism, Single Nucleotide/genetics , Adult , Analysis of Variance , Female , Gene Frequency , Genotype , Humans , Male , Methionine/genetics , Neuropsychological Tests , Psychiatric Status Rating Scales , Valine/genetics , Young AdultABSTRACT
In the present study, we have tested the hypothesis that brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism is associated with obsessive-compulsive disorder (OCD) and also investigated the association between the BDNF Val66Met polymorphism and the performance on tests measuring executive functions in a sample of patients with OCD. A total of 100 patients diagnosed with OCD according to DSM-IV criteria and 110 control subjects were included in this study. Single nucleotide polymorphism (G/A) leading to Val to Met substitution at codon 66 in BDNF was screened in the DNA samples of all participants. The genotype frequencies of BDNF Val66Met polymorphism were compared in OCD patients and healthy controls. The four subgroups of OCD and healthy control subjects, determined according to being Val homozygous or carrying a Met allele, were also compared according to their performance in a battery of neuropsychological tests of executive functions and verbal memory. There was no significant difference for the allele and genotype distributions of BDNF Val66Met polymorphism between the OCD and healthy control groups. Compared to the other three subgroups, OCD-Met carriers were slower on Trail-Making Test part A (TMT A), part B (TMT B) score and its speed-corrected score (TMT B-A). OCD-Met carriers had also poor performance on verbal fluency tasks and several CVLT measures compared only to the healthy control-Met carriers. These results demonstrate that the BDNF Val66Met polymorphism does not appear to be a risk factor for OCD. However, the presence of a BDNF Met allele, which is a known attenuator of BDNF activity, may be associated with a poorer executive functioning in OCD.
