The advances in understanding of glycans’ function and structure might offer new biomarkers of PTSD. The results from GWAS, combined with high throughput analysis of fluorescently labelled glycans, suggest B3GAT1, SLC9A9, MGA5, FUT8, FUT3/FUT6 and HNF1A genes to be associated with glycosylation in healthy individuals from Croatia. Determination of N-glycans associated with PTSD in plasma and from IgG, additionally corrected for a possible genetic and epigenetic influence, will improve our understanding of the biological underpinnings of PTSD. The proposed project aims to provide an association between genetic, epigenetic and glycomic mechanisms responsible for the resilience or vulnerability to develop PTSD after exposure to a traumatic event(s). The specific aims of the project are: 1) determination of plasma and IgG N-glycans in patients with PTSD and in matched control subjects; 2) confirmation of the polymorphisms in the specific selected genes which regulate protein glycosilation, determined by GWAS, in patients with PTSD and in matched control subjects; 3) evaluation of the influence of epigenetic regulation and expression of the HNF1A gene on protein glycosylation in patients with PTSD and in matched control subjects. This approach will offer integration and understanding of the multidimensional dataset and identify novel biomarkers of PTSD, as well as new targets and novel strategies to prevent development of PTSD after exposure to a trauma, or for therapeutic intervention in PTSD.