ASSOCIATION OF NEUROPEPTIDE S RECEPTOR 1 AND GLUTAMATE DECARBOXYLASE 1 GENE POLYMORPHISMS WITH POSTTRAUMATIC STRESS DISORDER

Background: Posttraumatic stress disorder (PTSD) is an anxiety disorder caused by highly traumatic experiences. The aim of this study was to investigate the influence of single nucleotide polymorphisms (SNPs) in the neuropeptide S receptor 1 (NPSR1) and the glutamate decarboxylase 1(GAD1) gene on PTSD and its psychopathological aspects among individuals affected by the Balkan wars during the 90s. Subjects and methods: This study was conducted as part of the South Eastern Europe (SEE) study on molecular mechanisms of PTSD. It comprised 719 participants (539 males), including those with current PTSD, remitted PTSD and healthy volunteers. Psychometric evaluation was performed using the Mini International Neuropsychiatric Interview (M.I.N.I.), the Clinician Administrated PTSD Scale (CAPS) andthe Brief Symptom Inventory (BSI). We examined NPSR1 single nucleotide polymorphism (SNP) rs324981 and GAD1 variant rs3749034 genotypes. Case-control analyses were carried out using logistical regression to determine genotype differences between all patients that had either current or remitted PTSD and control individuals. To analyse the influence of the analysed SNPs on PTSD severity, we performed linear regression analyses with CAPS and BSI within each of the two patient groups separately. All of the calculations were performed for additive allelic, recessive, dominant and genotypic models. Results: We observed a nominally significant association for the major allele (G) of GAD1 rs3749034 with an increased risk to develop PTSD in a case control analysis in the recessive model (P=0.0315, odds ratio=0.47, SE=0.35). In contrast, a nominally significant association of the minor allele (A) with higher CAPS scores was identified within the patient group with lifetime PTSD in the dominant model (P=0.0372, ????=6.29, SE=2.99). None of these results did withstand correction for multiple tests. No nominal significant results of GAD1 rs3749034 were found with regard to the intensity of psychological BSI symptoms. Case control analyses of NPSR1 rs324981 revealed a nominally significant higher risk for homozygous T allele carriers to develop PTSD (P=0.0452) in the recessive model. On the other hand, the T allele showed a nominally significant association with higher BSI scores in patients suffering from lifetime PTSD in the recessive model (P=0.0434). Again, these results were not significant anymore after correction for multiple tests. No associations of NPSR1 rs324981 and CAPS score was identified. Conclusion: The findings of this study provide some evidence that the NPSR1 and GAD1 polymorphisms might play a role in the development of war-related PTSD and its related psychological expressions. Further research is needed to elucidate the interactions of specific gene variants and environmental factors in the development of PTSD

ASSOCIATIONS BETWEEN POLYMORPHISMS IN THE SOLUTE CARRIER FAMILY 6 MEMBER 3 AND THE MYELIN BASIC PROTEIN GENE AND POSTTRAUMATIC STRESS DISORDER

Background: Previous research showed inconsistent results concerning a possible association between solute carrier family 6 member 3 (SLC6A3) gene polymorphisms and dopamine symptoms of posttraumatic stress disorder (PTSD). Several studies also indicate that the myelin basic protein (MBP) gene is of importance in the etiology of several psychiatric disorders. The aim of this study was to investigate the relation of distinct SLC6A3 and MBP gene polymorphisms with PTSD and whether SLC6A3 and MBP genotypes contribute to PTSD symptom severity. Subjects and methods: The study included 719 individuals who had experienced war trauma in the South Eastern Europe (SEE). Genotypes of variable number tandem repeat (VNTR) polymorphism within the SLC6A3 gene were assessed in 696 participants, and the single nucleotide polymorphism (SNP) rs12458282 located within the MBP gene region was genotyped in a total of 703 subjects. The Mini International Neuropsychiatric Interview, the Clinical Administrated PTSD Scale (CAPS) and Brief Symptom Inventory (BSI), were used for data collection. Results: No significant differences concerning the investigated SLC6A3 and MBP polymorphisms was identifiable between PTSD and non PTSD participants. Also we could not detect significant influence of these distinct SLC6A3 and MBP alleles on the severity of PTSD symptoms (CAPS) or BSI scores. However, the results of MBP rs12458282 within the patients with lifetime PTSD may point to a possible correlation of the major allele (T) with elevated CAPS scores. Conclusions: Our results do not support an association of the analysed SLC6A3 and MBP gene polymorphisms with PTSD in war traumatized individuals. We found that there is a possibility for a correlation of the T allele rs12458282 within the MBP gene with higher CAPS scores in lifetime PTSD patients which would need to be tested in a sample providing more statistical power

ASSOCIATIONS OF GENE VARIATIONS IN NEUROPEPTIDE Y AND BRAIN DERIVED NEUROTROPHIC FACTOR GENES WITH POSTTRAUMATIC STRESS DISORDER

Background: Individuals who are exposed to traumatic events are at an increased risk of developing posttraumatic stress disorder (PTSD), a condition during which an individual\u27s ability to function is impaired by emotional responses to memories of those events. The gene coding for neuropeptide Y (NPY) and the gene coding for brain-derived neurotrophic factor (BDNF) are among the number of candidate gene variants that have been identified as potential contributors to PTSD. The aim of this study was to investigate the association between NPY and BDNF and PTSD in individuals who experienced war-related trauma in the South Eastern Europe (SEE) conflicts (1991-1999). Subjects and methods: This study included participants with current and remitted PTSD and healthy volunteers (N=719, 232 females, 487 males), who were recruited between 2013 and 2015 within the framework of the South Eastern Europe (SEE) - PTSD Study. Psychometric methods comprised the Mini International Neuropsychiatric Interview (M.I.N.I.), the Clinician Administered PTSD Scale (CAPS), and the Brief Symptom Inventory (BSI). DNA was isolated from whole blood and genotyped for NPY rs5574 via PCR - RFLP and NPY rs16147 and BDNF rs6265 using the KASP assay. Results: Tests for deviation from Hardy-Weinberg equilibrium showed no significant results. Analyses at the categorical level yielded no associations between the affected individuals and all three SNPs when compared to controls. Within lifetime PTSD patients, the major alleles of both NPY variants showed a nominally significant association with higher CAPS scores (p=0.007 and p=0.02, respectively). Also, the major allele of rs5574C>T was associated with higher BSI scores with a nominal significance among current PTSD patients (p=0.047). The results did not withstand a Bonferroni adjustment (????=0.002). Conclusion: Nominally significant associations between NPY polymorphisms and PTSD susceptibility were found that did not withstand Bonferroni correction

ASSOCIATION ANALYSIS OF MAOA AND SLC6A4 GENE VARIATION IN SOUTH EAST EUROPEAN WAR RELATED POSTTRAUMATIC STRESS DISORDER

Background: The aim of this study is to investigate the association of gene variations of the monoamine oxidase A (MAOA) and the serotonin transporter solute carrier family 6 member 4 (SLC6A4) gene with posttraumatic stress disorder (PTSD) severity and coping strategies in patients with war related PTSD. Subjects and methods: The study included 747 individuals who had experienced war trauma in the South Eastern Europe conflicts between 1991 and 1999. Genotyping of the MAOA VNTR and SLC6A4 tandem repeat polymorphism in combination with rs25531 was done in 719 participants: 232 females and 487 males. Among them, 369 have had current or lifetime PTSD and 350 have had no PTSD symptoms. For psychometric approach we used the Clinician Administrated PTSD Scale (CAPS), the Brief Symptom Inventory (BSI), the adapted Hoffman Lazarus Coping scale and a basic socio-demographic data questionnaire. Results: There were no significant intergroup (PTSD versus non PTSD) differences in the genotype distribution of MAOA and SLC6A4 gene polymorphisms. The primary finding of our study was that the MAOA short allele (MAOA-S) was nominally significantly associated with the severity of PTSD symptoms in the total subgroup of participants with lifetime PTSD; males for symptoms of hyperarrousal and females with symptoms of re-experience and hyperarousal. In our research the male subsample with current PTSD and MAOA-S genotype had nominally significantly higher scores for some positive coping strategies compared to those carrying the long allele genotype (MAOA-L). There was no significant association between the severity of PTSD symptoms, BSI phenotype, coping scores and the SLC6A4 genotype. Conclusion: The present results support the notion that MAOA VNTR gene variation modulates development and recovery of posttraumatic stress disorder in a war traumatised population, but did not support a connection between SLC6A4 gene variations and war related PTSD

GENETIC SUSCEPTIBILITY TO POSTTRAUMATIC STRESS DISORDER: ANALYSES OF THE OXYTOCIN RECEPTOR, RETINOIC ACID RECEPTOR-RELATED ORPHAN RECEPTOR A AND CANNABINOID RECEPTOR 1 GENES

Background: Exposure to life-threatening events is common and everyone will most likely experience this type of trauma during their ifetime. Reactions to these events are highly heterogeneous and seems to be influenced by genes as well. Some individuals will develop posttraumatic stress disorder (PTSD), while others will not. In this study, our aim was to analyze the correlation between single nucleotide polymorphisms (SNPs) within the oxytocin receptor (OXTR) gene (rs53576 and rs2254298), the RAR-related orphan receptor A (RORA) gene (rs8042149) and the cannabinoid receptor 1 (CNR1) gene (rs1049353) and PTSD. All candidate genes have been previously associated with stress related disorders and the reaction to traumatic events. Subjects and methods: Participants (N=719) have been exposed to war-related trauma during the war in South-Eastern Europe (Bosnia and Herzegovina, Croatia and Kosovo). We correlated the presence and absence of current and lifetime PTSD as well as PTSD severity (Clinician Administered PTSD scale (CAPS)) and current psychopathology (Brief Symptom Inventory (BSI) score) with the mentioned SNPs. DNA was isolated from whole blood and genotyped for OXTR rs2254298 and rs53576 following previously published protocols, for RORA rs8042149 via PCR-RFLP and CNR1 rs1049353 via KASP. Results: Nominally significant results were found for OXTR rs53576 in connection with the CAPS and BSI scores within lifetime PTSD patients. The additive allelic model indicated that G allele carriers achieved lower CAPS (p=0.0090) and BSI (p=0.0408) scores than participants carrying one or two copies of the A allele. These results did not withstand correction for multiple tests. No significant results were observed for OXTR rs2254298, RORA rs8042149 and CNR1 rs1049353 although the results for RORA showed a slight tendency that rs8042149 may influence the level of BSI scores in current PTSD patients. Conclusions: This study points to a role of the OXTR gene in PTSD and the related psychopathology following war related trauma

A CANDIDATE GENE ASSOCIATION STUDY OF FKBP5 AND CRHR1 POLYMORPHISMS IN RELATION TO WAR-RELATED POSTTRAUMATIC STRESS DISORDER

Background: Posttraumatic stress disorder (PTSD) is a highly frequent and disabling psychiatric condition among war-affected populations. TheFK506-binding protein 5 (FKBP5) gene and the corticotropin releasing hormone receptor 1 (CRHR1) gene have previously been implicated in an elevated risk of peritraumatic dissociation and PTSD development. Our aim was to investigate the association between FKBP5 and CRHR1 genotypes and PTSD diagnosis and severity among individuals who were affected by the Balkan wars during the 1990s. Subjects and methods: This study included participants with current PTSD, remitted PTSD and healthy volunteers (N=719, 487 males), who were recruited between 2013 and 2015 within the framework of the South Eastern Europe (SEE) - PTSD Study. Psychometric methods comprised the Mini International Neuropsychiatric Interview (M.I.N.I.), the Clinician Administrated PTSD Scale (CAPS), and the Brief Symptom Inventory (BSI). FKBP5 rs1360780 and CRHR1 rs17689918 genotypes were determined using a KASP genotyping assay. Results: Tests for deviation from Hardy Weinberg equilibrium showed no significant results. Logistic and linear regression was used to examine the associations between the FKBP5 SNP rs1360780 and the CRHR1 SNP rs17689918 with PTSD diagnosis and severity, as well as general psychiatric symptom severity, separately for current and remitted PTSD patients. There were nominally significant associations under a dominant model between the rs1360780 C allele and PTSD diagnosis as well as symptom severity, which however, were not significant anymore after Bonferroni adjustment (????=0.002). For CRHR1 rs17689918 no significant associations were detected. Conclusion: We found nominally, but not Bonferroni corrected significant associations between the FKBP5 polymorphism rs1360780 and PTSD susceptibility among individuals affected by the Balkan wars. For elucidating this gene’s real resilience/ vulnerability potential, environmental influences should be taken into account

THE ASSOCIATION OF CATECHOL-O-METHYL-TRANSFERASE AND INTERLEUKIN 6 GENE POLYMORPHISMS WITH POSTTRAUMATIC STRESS DISORDER

Background: Posttraumatic stress disorder (PTSD) is a disorder that occurs in some people who have experienced a severe traumatic event. Several genetic studies suggest that gene encoding proteins of catechol O-methyl-transferase (COMT) may be relevant for the pathogenesis of PTSD. Some researchers suggested that the elevation of interleukin-6 (IL6) correlates with major depression and PTSD. The aim of this study was to investigate whether the single nucleotide polymorphisms COMT rs4680 (Val158Met) and IL6 rs1800795 are associated with PTSD and contribute to the severity of PTSD symptoms. Subjects and methods: This study comprised 747 participants that experienced war between 1991 and 1999 in the South Eastern Europe conflicts. COMT rs4680 (Val158Met) and IL6 rs1800795 genotypes were determined in 719 participants (369 with and 350 without PTSD). The Mini International Neuropsychiatric Interview (M.I.N.I.), the Clinician Administrated PTSD Scale (CAPS) questionnaire and the Brief Symptom Inventory (BSI) were used for data collection. Results: Regarding the COMT gene polymorphism, the results of the regression analyses for BSI total score were significant in the lifetime PTSD group in the dominant (P=0.031) and the additive allelic model (P=0.047). Regarding the IL6 gene, a significant difference was found for the recessive model predicting CAPS total score in the lifetime PTSD group (P=0.048), and indicated an association between the C allele and higher CAPS scores. n the allelic, genotypic and rezessive model, the results for BSI total score were significant in the lifetime PTSD group (P=0.033, P=0.028 and P=0.009), suggesting a correlation of the C allele with higher BSI scores Conclusion: Although our nominally significant results did not withstand correction for multiple tests they may support a relevance of the COMT (Val158Met) and IL6 rs1800795 polymorphism for aspects of PTSD in war traumatized individuals

MOLECULAR MECHANISMS OF POSTTRAUMATIC STRESS DISORDER (PTSD) AS A BASIS FOR INDIVIDUALIZED AND PERSONALIZED THERAPY: RATIONALE, DESIGN AND METHODS OF THE SOUTH EASTERN EUROPE (SEE)-PTSD STUDY

Posttraumatic Stress Disorder (PTSD) is a major health problem in South Eastern Europe (SEE). Available treatment options are not efficient enough and the course is often chronic. Little is known about molecular mediators and moderators of pathogenesis and therapy. Genetic and epigenetic variation may be one central molecular mechanism. We therefore established a consortium combining clinical expertise on PTSD from SEE countries Bosnia-Herzegovina (Sarajevo, Tuzla and Mostar), Kosovo (Prishtina) and Croatia (Zagreb) with genetic and epigenetic competence from Germany (Würzburg) in 2011 within the framework of the DAAD (Deutscher Akademischer Austauschdienst)-funded Stability Pact for South Eastern Europe. After obtaining ethical votes and performing rater trainings as well as training in DNA extraction from EDTA blood between 2011 and 2013, we recruited 747 individuals who had experienced war-related trauma in the SEE conflicts between 1991 and 1999. 236 participants had current PTSD, 161 lifetime PTSD and 350 did not have and never had PTSD. Demographic and clinical data are currently merged together with genetic and epigenetic data in a single database to allow for a comprehensive analysis of the role of genetic and epigenetic variation in the pathogenesis and therapy of PTSD. Analyses will be done to a great degree by PhD students from participating SEE centers who in addition to participation in the project had an opportunity to take part in spring and summer schools of the DFG (Deutsche Forschungsgemeinschaft) funded Research Training Group (RTG) 1253 and thus meet PhD students from Germany and other countries We are confident that our project will not only contribute to a better understanding of genetic and epigenetic mechanisms of PTSD as a basis for future individualized and personalized therapies, but also to the academic development of South Eastern Europe

International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci.

The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations

Potential causal association between gut microbiome and posttraumatic stress disorder

Background: The causal effects of gut microbiome and the development of posttraumatic stress disorder (PTSD) are still unknown. This study aimed to clarify their potential causal association using mendelian randomization (MR). Methods: The summary-level statistics for gut microbiome were retrieved from a genome-wide association study (GWAS) of the MiBioGen consortium. As to PTSD, the Freeze 2 datasets were originated from the Psychiatric Genomics Consortium Posttraumatic Stress Disorder Working Group (PGC-PTSD), and the replicated datasets were obtained from FinnGen consortium. Single nucleotide polymorphisms meeting MR assumptions were selected as instrumental variables. The inverse variance weighting (IVW) method was employed as the main approach, supplemented by sensitivity analyses to evaluate potential pleiotropy and heterogeneity and ensure the robustness of the MR results. We also performed reverse MR analyses to explore PTSD’s causal effects on the relative abundances of specific features of the gut microbiome. Results: In Freeze 2 datasets from PGC-PTSD, eight bacterial traits revealed a potential causal association between gut microbiome and PTSD (IVW, all P < 0.05). In addition, Genus.Dorea and genus.Sellimonas were replicated in FinnGen datasets, in which eight bacterial traits revealed a potential causal association between gut microbiome and the occurrence of PTSD. The heterogeneity and pleiotropy analyses further supported the robustness of the IVW findings, providing additional evidence for their reliability. Conclusion: Our study provides the potential causal impact of gut microbiomes on the development of PTSD, shedding new light on the understanding of the dysfunctional gut-brain axis in this disorder. Our findings present novel evidence and call for investigations to confirm the association between their links, as well as to illuminate the underlying mechanisms