Our study of genetic homozygosity degree includes an analysis of the presence, distribution, and individual combination of 20 selected genetically controlled morphophysiological traits in the group of patients ( N = 93) with congenital hip dislocation (CDH) and in control sample consisting of schoolchildren from Belgrade ( N = 200). Assuming that CDH is a genetically controlled disease, we made a hypothesis that an increased homozygosity level, as well as the changed variability among the patients, could be a population-genetic parameter for the prediction of the illness. Taking into consideration our experience, as well as the experience of numerous scientists who studied the nature of the inheritance of mono-and oligogenically controlled qualitative traits, we applied a methodology to estimate the proportion of such homozygously recessive characters (HRC-TEST). This population-genetic study did not only show statistically significant difference of the middle values of genetic homozygosity (CDH: 7.1 ± 0.2; control: 5.2 ± 0.1), but of the differences in the type of distribution too, as well as the differences in the presence of certain individual combinations of such traits. The described methodology can be used in further analyses, with hope that it can be applied as an early prognosis for decreased resistance to different diseases.The frequencies of ABO blood types in the sample of CDH patients were similar to the average value of the Serbian population, while the percentage of blood group A is slightly increased. Comparing frequencies of Rh blood groups, there is no difference between tested samples. HUMAN GENETICS* This text was submitted by the authors in English.

In this population-genetic study, we compared morphological and genetic variability of a control group of individuals with that of developing and elite water polo players from Serbia, using a test of determination of homozygously recessive characteristics in humans (HRC-test). Comparisons of the frequencies of ABO and Rh blood types were also made for the groups examined. The degree of genetic homozygosity showed not only statistically significant differences in the mean values obtained for the studied samples (control group 5.1 +/- 0.2; emerging water polo players 3.5 +/- 0.1; elite water polo players 1.9 +/- 0.3 HRCs, out of 20 analysed characteristics), but also differences in the type of distribution, as well as the presence of specific combinations of such traits. During identification of swimming talents, the degree of genetic homozygosity showed a significant decrease, from 4.8 +/- 0.3 in the group of pre-competitive young boys, to 2.7 +/- 0.3 in selected adult team members, to only 1.9 +/- 0.3 in elite water polo players. In the group of pre-competitive young individuals, all characteristics tested also had homo-recessive combinations, while in the group of elite water polo players only 8 of 20 traits were expressed as homozygously recessive. In the group of elite water polo players, who were World and European champions as well as Olympic champions, the frequencies of the A and B blood types were low, AB was absent, and the frequency of the O blood type was high at 72.2% (i.e., almost twice the expected percentage).

No abstract

The study of Balkan endemic nephropathy (BEN) in the affected localities of southern Serbia shows population-genetic difference between samples of BEN affected individuals and control group consisting of non-affected individuals from the same localities. Detailed population-genetic study in village Chepure, which includes 20 large families where BEN is present in 646 (from first to fourth degree) relatives of probands, shows a familial character of disease as well as significant genetic influences in expression of the illness. Our study of genetic homozygosity degree includes an analysis of the presence, distribution and individual combination of 20 to 30 selected genetically controlled morphophysiological traits in the sample of BEN patients and in the control-healthy group. Assuming that BEN is genetically controlled disease, we made a hypothesis that an increased homozygosity level, as well as the changed variability among the patients, could be populationgenetic parameter for the prediction of the illness. Taking into consideration our experience, as well as the experience of numerous scientists who studied the nature of the inheritance of mono-and oligo-genically controlled qualitative traits, we applied a methodology to estimate the proportion of such homozygously recessive characters (HRC-test). This population-genetic study did not only show statistically significant difference of the mean values of genetic homozygosity (BEN: 8.7 ± 0.3; control: 7.6 ± 0.3), but of the differences in the type of distribution too, as well as the differences in the presence of certain individual combinations of such traits.

IntroductionAssuming that spina bifida (SB) is a genetically controlled disease, the aim of our study was to evaluate the degree of genetic homozygosity and the distribution of AB0 blood types among patients with SB occulta and SB aperta by the homozygously recessive characteristics (HRC) test.Material and methodsOur study included an analysis of the presence, distribution and individual combination of 15 selected genetically controlled morpho-physiological traits in a sample of 100 patients with SB (SB occulta N = 50 and SB aperta N = 50) and a control group of individuals (N = 100).ResultsWe found a statistically significant difference between the mean values for genetic homozygosity (SB 4.5 ±0.3; control 3.0 ±0.2, p < 0.001) and also differences in the presence of certain individual combinations of such traits. In 12 (80.0%) of the 15 observed characteristics, recessive homozygosity was expressed to a greater degree among the group of SB patients, while for 9 (60.0%) of the traits this level of difference was statistically significant (Σχ 2 = 266.3, p < 0.001). There was no difference in average homozygosity of such genetic markers between groups of SB occulta and SB aperta patients, but the type of individual variation in the two studied groups significantly differed. In the group of patients with SB the frequency of 0 blood group was significantly increased while B blood group was significantly decreased.ConclusionsOur results clearly show that there is a populational genetic difference in the degree of genetic homozygosity and variability between the group of patients with SB and individuals without clinical manifestations, indicating a possible genetic component in the aetiopathogenesis of spina bifida.