Colorectal cancer with its frequency, high mortality rate as well as many etiological unknowns is a challenge to contemporary science. Finally, genetic information could be used in near future for prevention of colorectal cancer, its early diagnosis and selection for the most suitable hospital treatment. In this study, we analysed genetic alterations of tumor suppressor genes and the possibility of quick and efficient screening method for identification of colorectal cancer. The study consisted of 54 samples of tumor and surrounding healthy tissue of patients with colorectal cancer, which is clasificated according to Bethesda and Amsterdams criterias. The investigation showed that genetic alterations of tumor suppressor gene NM 23 were present in 19/35 (54,29%) samples, and tumor suppressor gene p53 in 18/35 (51,43%), APC in 18/35 (51,43%), DCC2 tumor suppressor gene in 12/35 (34,29%), tumor suppressor gene RB1 in 8 /35 (22, 86%) and DCC 1 in 10/35 ( 28,57%) tumor tissue.

Genetic structure of two human populations, indigenous and migratory population in the area of the Tuzla region, was analyzed with respect to some static and dynamic-morphological properties. The analyzed genetic data were collected by direct observation and survey of 472 pupils of school age. The investigated parameters of genetic heterogeneity were estimated by: analysis of the frequency of recessive phenotypes for every observed property, t-test analysis, and assessment of intragroup variation by analysis of Wahlund variance. Based on the obtained results it was observed that the frequency of the recessive homozygote for most of the analyzed properties was slightly higher in migratory populations. All values obtained by Wahlund variance analysis indicated a small genetic differentiation.

The objectives of this research were to establish the recessive phenotype frequency of the(in)ability of tongue rolling (fr) and frequency of the(in)ability of tongue folding. The data were collected by means of direct analysis and interviews with pupils from 5th to 8th grade. The research was conducted in rural and urban areas of Zivinice Municipality (OS Zivinice and OS Basigovci). The sample comprised 438 persons of both sexes (202 boys and 236 girls) 11-16 years of age. 197 respondents were from urban and 241 from rural area. The analysis of the obtained results showed that the phenotype frequency of the (in)ability of tongue rolling in Zivinice Municipality is 20,30% with relative frequency of recessive allele qr=0,45, while in the Basigovci area the phenotype frequency of the(in)ability of tongue rolling is 41,90%, with relative frequency of recessive allele qr=0,64. The phenotype frequency of the(in)ability of tongue folding in Zivinice is 32,48%, relative frequency of recessive allele qu=0,56, while the incidence of same phenotipe in Basigovci is 44,81%, and relative frequency of recessive allele is qu=0,66. The analysis of the results in Živinice Municipality show that the frequency of recessive allele is not different from the one found in the previous researeches in the regions of B&H and has approximate value of the frequency of reccesive allele from Gradacac qr=0,55.