The mean age was 37.7, SD = selleck chem inhibitor 12.5. The control group was matched with age and sex. The study was approved by our local ethics committee.2.3. GenotypingDNA was extracted from using the salting out method [19]. SNP selection was carried out under the following criteria: functionality (in experimental functional studies), high frequency (MAF > 0.05), indication as a tag SNP in HapMap, or previously reported associations with psychiatric disorders (both positive and negative findings). The SNPs chosen included both coding regions of known functionality and noncoding regions (introns, UTRs) that could affect gene regulation. The NR3C1, CRHR1, and AVPR1b polymorphisms were genotyped using TaqMan SNP Genotyping assays (Applied Biosystems) and TaqMan Genotyping Master Mix.

The list of SNPs analysed and the ID numbers of the TaqMan assays were used according to previously described findings [20]. For each reaction plate, nontemplate controls (water) and genomic control DNA samples were included. To check for genotyping accuracy control TaqMan SNP genotyping assay was performed, 15% of randomly chosen samples from both groups, and identical genotypes were identified in all repeated samples. The clinical status of the subjects was not known during genotyping. The genotyping success rates were between 96.03% and 98.97%. The total number of genotyped patients differs on the different SNPs due to genotyping errors and therefore exclusions from further studies.2.4. Statistical AnalysisTwo-tailed Pearson’s chi-squared (��2) test and Fisher’s exact test were, respectively, used to test differences in the genotypic and allelic distribution between the groups of patients and the control subjects.

Two-tailed power analysis was also performed. Calculations were performed using Statistica version 9.0. Odds ratios were calculated using 2 �� 2 contingency tables by using Fisher’s exact test in a demo version of GraphPad InStat 3 software. Linkage disequilibrium (LD) between the CRHR1, AVPR1b, and NR3C1 polymorphisms was examined by pairwise comparisons of r2 and D�� using Haploview version 4.1 [21]. Corrections for multiple testing were performed for multiple comparisons in the haplotype analysis and were completed for 10,000 permutations.Higher-order gene-gene interactions among the tested SNPs were analysed using the nonparametric and genetic model-free multifactor dimensionality reduction (MDR) approach (v.

2.0 beta 8.3). All interactions were tested using 10-fold cross-validation in an exhaustive search considering all possible SNP combinations. The model with the highest testing balance accuracy and cross-validation consistency of >5 out of 10 was selected as the ��best model.�� Statistical Cilengitide significance was determined using a 1000-fold permutation test (MDR permutation testing module, v.1.0 beta 2). The software is available online (http://www.epistasis.org/).The power to detect an association for an odds ratio of 1.5 for our sample was about 80% for each SNP.3.