Posttraumatic Stress Disorder (PTSD) can develop after experiencing or witnessing any severe traumatic event such as combat. Point prevalence rates in war-affected regions, e.g. Bosnia-Herzegovina and Kosovo, range from 18% to 35%. Noradrenergic dysfunction as represented by e.g. elevated noradrenaline concentrations in the cerebrospinal fluid of PTSD patients is known to play a substantial role in the pathogenesis of PTSD symptoms [1]. Epigenetic regulation (i.e. DNA methylation) is strongly suggested to moderate the interaction between environmental influences and a genetic predisposition. Therefore, differential methylation of genes involved in the noradrenergic system such as the monoamine oxidase A (MAOA) gene might be part of the complex biological underpinnings of a dysregulated noradrenergic system and thereby contribute to PTSD risk. The present study aimed at investigating MAOA gene methylation as a possible epigenetic marker of PTSD status and severity in a sample comprising patients with PTSD and healthy controls recruited from war-affected regions in Bosnia-Herzegovina, Croatia and Kosovo. DNA methylation levels of MAOA (exonI/intronI region) were analyzed in PTSD patients [N=216; m=157, age (mean±s.d.): 50.08±6.74 years], remitted PTSD patients [N=151; m=98, age (mean±s.d.): 49.48±8.20 years] and healthy controls [N=349, m=232, age (mean±s.d.): 48.81±8.50 years] by direct sequencing of sodium bisulfite-treated DNA followed by semi-quantitative analysis of the sequencing results via the Epigenetic Sequencing Methylation software. Severity of PTSD symptoms was assessed by the Clinician-Administered PTSD Scale (CAPS). All participants were assessed for potential confounders of methylation (sex, age, or smoking status). Possible categorical differences were analyzed by (M)ANCOVAs with age and smoking status as covariates. Post-hoc tests (Bonferroni) were performed to test individual differences in methylation across groups. Associations between dimensional measures were analyzed performing partial correlation analyses controlled for age and smoking status. In the male subsample, analyses revealed significant methylation differences at three out of 13 CpG sites between patients with current PTSD, remitted PTSD patients, and healthy controls. Post-hoc tests showed trend-wise significant (padjusted<0.1) to significant (padjusted<0.05) hypermethylation in current PTSD patients when compared to healthy controls at CpG3 (padjusted=0.089), CpG12 (padjusted=0.011) and CpG13 (padjusted=0.086) as well as at CpG3 (padjusted=0.029), CpG12 (padjusted<0.001), and CpG13 (padjusted=0.058) when compared to remitted PTSD patients. Additionally, PTSD symptom severity (total CAPS scores) was positively correlated with average MAOA methylation (r=0.206, p=0.016), methylation at CpG3 (r=0.186, p=0.033), CpG12 (r=0.306, p<0.001), and CpG13 (r=0.277, p=0.001) in male patients with a current PTSD diagnosis. In the female subsample, we failed to observe association of MAOA methylation with either current or remitted PTSD, while there was a positive correlation between MAOA methylation and symptom severity (r=0.294, p=0.033). The results of the present study for the first time suggest MAOA hypermethylation – possibly resulting in an increased noradrenergic tonus – as a disease status and severity marker of PTSD particularly in male patients. Given robust replication, MAOA hypermethylation might thus serve as an epigenetic marker within the complex risk factor constellation of PTSD. Furthermore, applying a personalized pharmaco-therapeutic approach, anti-adrenergic agents might prove to be beneficial in counterbalancing increased noradrenergic signalling specifically in male PTSD patients displaying MAOA hypermethylation.

Increased sympathetic noradrenergic signaling is crucially involved in fear and anxiety as defensive states. MicroRNAs regulate dynamic gene expression during synaptic plasticity and genetic variation of microRNAs modulating noradrenaline transporter gene (SLC6A2) expression may thus lead to altered central and peripheral processing of fear and anxiety. In silico prediction of microRNA regulation of SLC6A2 was confirmed by luciferase reporter assays and identified hsa-miR-579-3p as a regulating microRNA. The minor (T)-allele of rs2910931 (MAF(cases) = 0.431, MAF(controls) = 0.368) upstream of MIR579 was associated with panic disorder in patients (p(allelic) = 0.004, n(cases) = 506, n(controls) = 506) and with higher trait anxiety in healthy individuals (p(ASI) = 0.029, p(ACQ) = 0.047, n = 3112). Compared to the major (A)allele, increased promoter activity was observed in luciferase reporter assays in vitro suggesting more effective MIR579 expression and SLC6A2 repression in vivo (p = 0.041). Healthy individuals carrying at least one (T)-allele showed a brain activation pattern suggesting increased defensive responding and sympathetic noradrenergic activation in midbrain and limbic areas during the extinction of conditioned fear. Panic disorder patients carrying two (T)-alleles showed elevated heart rates in an anxiety-provoking behavioral avoidance test (F(2, 270) = 5.47, p = 0.005). Fine-tuning of noradrenaline homeostasis by a MIR579 genetic variation modulated central and peripheral sympathetic noradrenergic activation during fear processing and anxiety. This study opens new perspectives on the role of microRNAs in the etiopathogenesis of anxiety disorders, particularly their cardiovascular symptoms and comorbidities.

The molecular genetics of panic disorder (PD) with and without agoraphobia (AG) are still largely unknown and progress is hampered by small sample sizes. We therefore performed a genome-wide association study with a dimensional, PD/AG-related anxiety phenotype based on the Agoraphobia Cognition Questionnaire (ACQ) in a sample of 1370 healthy German volunteers of the CRC TRR58 MEGA study wave 1. A genome-wide significant association was found between ACQ and single non-coding nucleotide variants of the GLRB gene (rs78726293, P =3.3 × 10 −8 ; rs191260602, P =3.9 × 10 −8 ). We followed up on this finding in a larger dimensional ACQ sample ( N =2547) and in independent samples with a dichotomous AG phenotype based on the Symptoms Checklist (SCL-90; N =3845) and a case–control sample with the categorical phenotype PD/AG ( N combined =1012) obtaining highly significant P -values also for GLRB single-nucleotide variants rs17035816 ( P =3.8 × 10 −4 ) and rs7688285 ( P =7.6 × 10 −5 ). GLRB gene expression was found to be modulated by rs7688285 in brain tissue, as well as cell culture. Analyses of intermediate PD/AG phenotypes demonstrated increased startle reflex and increased fear network, as well as general sensory activation by GLRB risk gene variants rs78726293, rs191260602, rs17035816 and rs7688285. Partial Glrb knockout mice demonstrated an agoraphobic phenotype. In conjunction with the clinical observation that rare coding GLRB gene mutations are associated with the neurological disorder hyperekplexia characterized by a generalized startle reaction and agoraphobic behavior, our data provide evidence that non-coding, although functional GLRB gene polymorphisms may predispose to PD by increasing startle response and agoraphobic cognitions.

To identify common variants contributing to normal variation in two specific domains of cognitive functioning, we conducted a genome-wide association study (GWAS) of executive functioning and information processing speed in non-demented older adults from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) consortium. Neuropsychological testing was available for 5429–32 070 subjects of European ancestry aged 45 years or older, free of dementia and clinical stroke at the time of cognitive testing from 20 cohorts in the discovery phase. We analyzed performance on the Trail Making Test parts A and B, the Letter Digit Substitution Test (LDST), the Digit Symbol Substitution Task (DSST), semantic and phonemic fluency tests, and the Stroop Color and Word Test. Replication was sought in 1311-21860 subjects from 20 independent cohorts. A significant association was observed in the discovery cohorts for the single-nucleotide polymorphism (SNP) rs17518584 (discovery P-value=3.12 × 10−8) and in the joint discovery and replication meta-analysis (P-value=3.28 × 10−9 after adjustment for age, gender and education) in an intron of the gene cell adhesion molecule 2 (CADM2) for performance on the LDST/DSST. Rs17518584 is located about 170 kb upstream of the transcription start site of the major transcript for the CADM2 gene, but is within an intron of a variant transcript that includes an alternative first exon. The variant is associated with expression of CADM2 in the cingulate cortex (P-value=4 × 10−4). The protein encoded by CADM2 is involved in glutamate signaling (P-value=7.22 × 10−15), gamma-aminobutyric acid (GABA) transport (P-value=1.36 × 10−11) and neuron cell-cell adhesion (P-value=1.48 × 10−13). Our findings suggest that genetic variation in the CADM2 gene is associated with individual differences in information processing speed.

Introduction Depression and obesity are highly prevalent major public health problems that frequently co-occur. Shared aetiological factors have been found between depression and obesity. The role of the fat mass and obesity associated ( FTO ) gene in body mass index (BMI) and obesity has been confirmed in many independent studies. Recently, we reported the first study implicating FTO in the association between depression and obesity. Objectives We aimed to confirm these findings by investigating the FTO rs9939609 polymorphism in a meta-analysis of 13,701 individuals. Methods The sample consists of 6,902 depressed cases and 6,799 controls from five studies (Radiant, PsyCoLaus, GSK, MARS and NESDA/NTR). Common inclusion criteria were information available on a lifetime DSM-IV diagnosis of major depressive disorder (MDD), BMI and genotype data. Linear regression models for quantitative traits assuming an additive genetic model were performed to test for association and interaction between rs9939609, BMI and depression. Fixed and random-effects meta-analyses were performed. Results Fixed-effects meta-analyses support a significant association between rs9939609 polymorphism and BMI (whole-sample: s=0.07, p=1.29×10 -12 , depressive-cases: s=0.12, p=6.92×10 -12 ). No association was found in controls (s=0.02, p=0.15). Meta-analyses further support a significant interaction between FTO , BMI and depression (fixed-effects: s=0.13, p=3.087×10 -7 ; random-effects: s=0.12, p=0.027), wherein depressed carriers of the risk allele have an additional increase of 2.2% in BMI. Conclusions This meta-analysis demonstrates a significant interaction between FTO , depression and BMI, indicating that depression increases the effect of FTO on BMI. Depression-related alterations in key biological processes may interact with the rs9939609 FTO risk allele to increase obesity risk.

Matrix metalloproteinase 9 (MMP9) plays an important role in the pathogenesis of multiple sclerosis (MS). However, the impact of genetic variants affecting MMP9 on MS susceptibility is still in debate. We could not detect an association of MMP9 SNPs with MS on a genome-wide significance level by SNP genotyping, followed by imputation of SNPs within a region stretching 2Mbp up- and down-stream of MMP9. Rs6073751, located within WFDC2, was found associated with MS most strongly. Rs3918242, associated with MS according to previous reports, showed nominal significance only. Meta-analysis of our own and published data did not confirm this effect.

The diacylglycerol kinase eta (DGKH) gene, first identified in a genome-wide association study, is one of the few replicated risk genes of bipolar affective disorder (BD). Following initial positive studies, it not only was found to be associated with BD but also implicated in the etiology of other psychiatric disorders featuring affective symptoms, rendering DGKH a cross-disorder risk gene. However, the (patho-)physiological role of the encoded enzyme is still elusive. In the present study, we investigated primarily the influence of a risk haplotype on amygdala volume in patients suffering from schizophrenia or BD as well as healthy controls and four single nucleotide polymorphisms conveying risk. There was a significant association of the DGKH risk haplotype with increased amygdala volume in BD, but not in schizophrenia or healthy controls. These findings add to the notion of a role of DGKH in the pathogenesis of BD.

Interferons-β (IFN-β) are the most widely used immunomodulatory drugs for treatment of multiple sclerosis (MS). The development of neutralizing antibodies (NABs) against IFN-β is one of the main reasons for treatment failure. While formulation of the drug has a proven impact on the development of NABs, the genetic predisposition to develop antibodies is poorly understood. We performed genome-wide single-nucleotide polymorphism (SNP) genotyping in 362 MS patients of whom 178 had developed and 184 had not developed antibodies on IFN-β therapy. Four candidate SNPs were validated in an independent cohort of 350 antibody-positive and 468 antibody-negative MS patients. One SNP within the human leucocyte antigen (HLA) region (rs9272105, P -value: 3.56 × 10 −10 ) and one SNP in an intergenic region on chromosome 8q24.3 (rs4961252, P -value: 2.92 × 10 −8 ) showed a genome-wide significant association with the anti-IFN-β antibody titers. We found no interaction between the genome-wide significant SNPs (rs9272105 and rs4961252) in our study and the previously described HLA-DR * 0401 or * 0408 alleles, indicating an additive effect of SNPs and HLA alleles. Testing for these SNPs and the HLA-DR * 0401 or * 0408 alleles allows to identify patients at risk to develop antibodies to IFN-β and may provide helpful information for individual treatment decisions.

Background: Data from clinical studies and results from animal models suggest a major involvement of the neurotrophin system in the pathology of depression and antidepressant treatment response. Genetic variations within the genes coding for the brain-derived neurotrophic factor (BDNF) and its key receptor Trkb (NTRK2) may therefore influence the response to antidepressant treatment. Methods: We performed a pharmacogenetic study in 398 at least moderately severe depressed Caucasian inpatients participating in the Munich Antidepressant Response Signature (MARS) study. We tested for single marker association of 82 SNPs tagging the BDNF and NTRK2 gene regions with antidepressant treatment response. In an attempt for replicating the results, we genotyped all nominally significant associated SNPs of the discovery analysis in additional 249 patients of the MARS study and 247 depressed inpatients from an independent sample recruited in Münster, Germany. Results: We identified several SNPs of the BDNF and NTRK2 gene that were significantly associated with antidepressant treatment response. We could partly replicate these associations in a meta-analysis of all samples (total of 894 patients), withstanding correction for multiple testing and adjustment for confounding variables. Conclusions: These findings provide further substantiation for a possible involvement of genetic variations in the BDNF and NTRK2 gene in the antidepressant treatment response.

Objectives -Recently, associations of several single-nucleotide polymorphisms (SNPs) within the CLEC16A gene with multiple sclerosis (MS), type-I diabetes, and primary adrenal insufficiency were reported.Methods -We performed linkage disequilibrium (LD) fine mapping with 31 SNPs from this gene, searching for the region of highest association with MS in a German sample consisting of 603 patients and 825 controls.Results -Four SNPs located in intron 19 of the CLEC16A gene were found associated. We could replicate the finding for SNP rs725613 and were able to show for the first time the association of rs2041670, rs2080272 and rs998592 with MS.Conclusion -All described base polymorphisms are mapping to one LD block of approximately 50 kb within intron 19 of the CLEC16A gene, suggesting a pivotal role of this region for susceptibility of MS and possibly also for other autoimmune diseases.