AIM To study the distribution of allele frequencies of 15 short tandem repeat (STR) loci in a representative sample of Croatian population. METHODS A total of 195 unrelated Caucasian individuals born in Croatia, from 14 counties and the City of Zagreb, were sampled for the analysis. All the tested individuals were voluntary donors. Buccal swab was used as the DNA source. AmpFlSTR Identifiler was applied to simultaneously amplify 15 STR loci. Total reaction volume was 12.5 microL. The PCR amplification was carried out in PE Gene Amp PCR System Thermal Cycler. Electrophoresis of the amplification products was preformed on an ABI PRISM 3130 Genetic Analyzer. After PCR amplification and separation by electrophoresis, raw data were compiled, analyzed, and numerical allele designations of the profiles were obtained. Deviation from Hardy-Weinberg equilibrium, observed and expected heterozygosity, power of discrimination, and power of exclusion were calculated. Bonferroni's correction was used before each comparative analysis. RESULTS We compared Croatian data with those obtained from geographically neighboring European populations. The significant difference (at P<0.01) in allele frequencies was recorded only between Croatian and Slovenian populations for vWA locus. There was no significant deviation from Hardy-Weinberg equilibrium for all the observed loci. CONCLUSION Obtained population data concurred with the expected "STR data frame" for this part of Europe.

An exposure to extreme trauma events leads to posttraumatic stress disorder (PTSD) in up to 14-50% of war survivors. Recent findings suggest that genetic factors could play a certain role in PTSD development. In order to illustrate this possibility, we present results of a pilot study on gender specific sample of Sarajevo civilians immediately after the war cessation. During the period 1992-1995, Sarajevo civilians experienced continuous life threatening events with a great risk of developing PTSD in such conditions. Our study included 100 women adjusted to same socio-demographic characteristics. All women were interviewed using Harvard Trauma Questionnaire (HTQ) and divided into two groups (domestic and returnees) according to exposure length to extreme war life events of six or forty-three months. Above 50% of total analysed sample fulfilled criteria for PTSD. Regarding duration in trauma exposure no significant difference between these two groups were found. The only significant predictor found was physical abuse (p>0.01) that still cannot explain why some women develop PTSD while others not. Several years after the war, PTSD frequencies are decreased and disorder became chronic and more severe. However, the PTSD prevalence remains high when compared to general population rates. Therefore, Sarajevo population being exposed for almost four years to extreme war life events represents unique model for comparative research on PTSD etiology within the light of latest findings in molecular genetics of PTSD.