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's 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 (α=0.002). CONCLUSION: Nominally significant associations between NPY polymorphisms and PTSD susceptibility were found that did not withstand Bonferroni correction.