Suzana Cvjeticanin

Population genetic analyses of susceptibility to developing alcohol dependence

Acting on the assumption that susceptibility to alcohol dependence is genetically controlled, we have developed a hypothesis that a generally increased homozygosity level, as well as a changed variability in the group of alcoholics, could be a population genetic parameter for predicting this dependence. A morphophysiological test was used to identify the proportion of homozygously recessive characteristics (HRC test), so that the comparison of presence and distribution of the 25 selected homorecessive traits was carried out between the group of 100 cured alcoholics (the A group), and a control group consisting of 100 non-alcoholics (the C group). This population genetic study revealed not only a statistically significant difference in the mean values of genetic homozygosity (A: 9.3 ± 0.2, C: 8.2 ± 0.2), but also the differences in the distribution type, as well as in the variances of presence of certain specific combinations of such traits. In 18 of the 25 observed characteristics, recessive homozygosity was expressed to a greater degree among the group of alcoholics, while for 10 of the traits this level of difference was statistically significant. The fact that the genes controlling such qualitative recessive traits are distributed in different human chromosomes as their visible markers, could indicate that the genetic homozygosity degrees are visibly higher in the sample of alcohol dependents when compared to the group of individuals free from such dependence. Further application of the HRC testing as an easy procedure may have its practical use in identifying the presence of such indicators in young individuals in order to detect a possible future inclination to alcoholism.

Degree of genetic homozygosity and distribution of AB0 blood types among patients with spina bifida occulta and spina bifida aperta

Introduction Assuming 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 methods Our 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). Results We 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. Conclusions Our 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.

Morphogenetic variability during selection of elite water polo players

Abstract 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).

Distribution of affected muscles and degree of neurogenic lesion in patients with spina bifida

Introduction Patients with spina bifida in the lumbosacral region usually have various degrees of motor and sensory dysfunctions of the lower extremities and anal sphincter. The aim of our study was to evaluate the distribution and differences in frequencies of affected muscles, number of affected muscles and degree of neurogenic lesion between patients with spina bifida occulta (SBO) and spina bifida aperta (SBA). Material and methods In 100 patients with SB, 6 muscles in the lower limbs were separately analysed. Due to the number of affected muscles, we evaluated 5 groups of patients: with 1 affected muscle, 2 affected muscles, 3 affected muscles, 4 affected muscles and 5 affected muscles. Three degrees of neurogenic lesions were assessed: mild, moderate and severe. Results The tibialis anterior muscle was most frequently affected in SB patients. The outer anal sphincter was frequently affected in the group of SBA patients. Single muscle affection is frequent in the group of patients with SBO, while in the group of patients with SBA, 4 muscles were significantly frequently affected. The great majority of patients (45.46%) with affected outer anal sphincter (OAS) in the group of SBO were without affection of other muscles, while for the SBA group it was for every third patient. Mild neurogenic lesion was significantly frequent in SBO patients, while severe form was significantly frequent in SBA patients. Conclusions Patients with SBO usually present with mild to moderate clinical presentation, while multiple root involvement and severe degree of neurogenic lesion is associated more frequently with SBA.

Population genetic analyses of susceptibility to increased body weight.

Introduction Obesity is a complex condition with multifactorial origin. Assuming that such a state is genetically controlled, the aim of our study was to evaluate the degree of genetic homozygosity among overweight and obese individuals by the homozygously recessive characteristics (HRC) test. Material and methods We analysed the presence, distribution and individual combination of 15 selected genetically controlled recessive phenotype traits in a sample of 140 individuals with increased body mass index (overweight individuals n = 100 and obese individuals n = 40) and a control group of normal weight individuals (n = 300). Results Obese individuals have significantly higher mean values for genetic homozygosity than those with normal weight (normal weight: 3.61 ±1.48; obese: 4.13 ±1.47, p < 0.05) and difference in the presence of certain individual combinations of evaluated phenotype traits (Σχ2 = 76.9; p < 0.01). There was no difference in average homozygosity of such genetic markers between groups of normal weight and overweight individuals (normal weight: 3.61 ±1.48; overweight: 3.93 ±1.51, p > 0.05) and between groups of overweight and obese individuals (overweight: 3.93 ±1.51; obese: 4.13 ±1.47, p > 0.05). There is no difference in the presence of certain individual combinations of evaluated phenotype traits between overweight and obese individuals (Σχ2 = 20.6; p > 0.05). Conclusions There is a populational genetic difference in the degree of genetic homozygosity and variability between the group of normal weight and group of obese individuals, indicating a possible genetic component. Overweight and obese individuals have a genetic predisposition, but different expression of genetic loads could be one of the possible explanations for different susceptibility to increase of fat mass and body mass index.

The Gender Impact on Morphogenetic Variability in Coronary Artery Disease: A Preliminary Study

We analyzed morphogenetic variability and degree of genetic homozygosity in male and female individuals with coronary artery disease (CAD) versus unaffected controls. We have tested 235 CAD patients; 109 were diagnosed also with diabetes mellitus (DM) and 126 with hypertension (HTN). We additionally evaluated 152 healthy individuals without manifested CAD. For the evaluation of the degree of recessive homozygosity, we have performed the homozygously recessive characteristics (HRC) test and tested 19 HRCs. In controls, the frequency of HRC for males was 2.88 ± 1.89, while for females, it was 3.65 ± 1.60. In the CAD group, the frequency of HRC for males was 4.21 ± 1.47, while for females, it was 4.73 ± 1.60. There is significant difference in HRC frequencies between controls and CAD separately for males (p < 0.001) and females (p < 0.001). The same applies between controls and CAD with DM (males: p < 0.001 and females: p = 0.004), and controls and CAD with HTN (males: p < 0.001 and females: p < 0.001). There is no significant difference in HRC frequencies between the group of CAD with DM and the group of CAD with HTN (males: p = 0.952 and females: p = 0.529). Our findings point to the increased degree of recessive homozygosity and decreased variability in both genders of CAD patients versus controls, indicating the potential genetic predisposition for CAD.

Morphogenetic Variability and Hypertension in Ischemic Stroke Patients—Preliminary Study

In this study, we evaluated and compared the morphogenetic variability and the degree of recessive homozygosity in patients with manifested ischemic stroke compared to healthy controls. We have evaluated 120 patients with manifested ischemic stroke, of which 64 did not have hypertension and 56 have hypertension. For comparison, we additionally tested 194 healthy individuals without manifested ischemic stroke (controls). For the estimation of the degree of recessive homozygosity, we have performed the homozygously recessive characteristics (HRC) test and tested 19 HRCs. There was a significant difference in the individual variations of 19 HRCs between the controls and patients with manifested ischemic stroke (∑χ2 = 60.162, p < 0.01). The mean values of the tested HRCs significantly differed between the controls and group with manifested ischemic stroke (Controls − 5.71 ± 1.61, Ischemic stroke group − 6.25 ± 1.54, p = 0.012). For the tested individuals with hypertension, the mean values of HRCs did not significantly differ between the controls and those that had manifested ischemic stroke (Controls − 5.28 ± 1.75, Ischemic stroke group − 5.64 ± 1.48, p = 0.435). We found a significant difference in the frequencies of HRCs between those with and without hypertension for controls (p < 0.003) and for those with manifested ischemic stroke (p < 0.001). There are increased degrees of recessive homozygosity along with decreased variability in patients with manifested ischemic stroke compared to controls.

Genetic and Environmental Dispositions for Cardiovascular Variability: A Pilot Study

Background: The aim of our study was to evaluate the degree of genetic homozygosity in the group of patients with coronary artery disease (CAD), as well as to evaluate morphogenetic variability in CAD patients regarding the presence of investigated risk factors (RF) compared to a control sample of individuals. Additionally, we aimed to evaluate the distribution of ABO blood type frequencies between tested samples of individuals. Methods: This study analyzed individual phenotype and morphogenetic variability of 17 homozygously-recessive characteristics (HRC), by using HRC test in a sample of 148 individuals in CAD patients group and 156 individuals in the control group. The following RF were analyzed: hypertension, diabetes mellitus, hyperlipidemia, and smoking. Results: The mean value of HRC in CAD patients is significantly higher, while variability decreases compared to the control sample (CAD patients: 4.24 ± 1.59, control sample: 3.75 ± 1.69; VCAD-patients = 37.50%, VC = 45.07%). There is a significant difference in individual variations of 17 HRC between control sample and CAD patients (χ2 = 169.144; p < 0.01), which points out to different variability for tested genes. Mean values of HRC significantly differed in CAD patients in regard to the number of RF present. A blood type (OR = 1.75) is significant predictor for CAD, while O blood type (OR = 0.43) was significantly associated with controls. Conclusion: There is a higher degree of recessive homozygosity in CAD patients versus individuals in the control sample, and the presence of significant variations in the degree of recessive homozygosity as the number of tested RF increases.

Anthropogenetic Variability in the Group of Individuals with Febrile Seizures: Population-Genetic Study

Febrile seizures (FS) are the most common neurological disorder in childhood and are a great stress for parents due to their dramatic clinical appearance. Using test for determination of homozygously recessive characteristics in humans (HRC test) we analyzed presence, distribution, and individual combination of 20 selected genetically controlled morphophysiological traits among FS patients (N=121) and control (N=121) to determine a possible deviation in the homozygosity level and genetic loads in the group of affected children and whether there is a predisposition to the occurrence of FS. The results of our study show a statistically significant difference in the mean values of the HRC tested (x¯HRC/20 CN = 3.2 ± 0.2; x¯HRC/20 FS = 4.6 ± 0.2, t= 5.74 , p< 0.0001), as well as in the distribution and variability of two studied samples (VC=55,3%, VFS= 39,6%), which indicates a complex polygenic difference among the tested groups of subjects. The differences in the degree of genetic homozygosity and variability are also present between the genders (t Cf/FSf = 4.12; t Cm/FSm = 3.98; p <0.0001) (VCf=56.9%, VFSf= 39.3%; VCm=54.1%, VFSm=40.1%). Obtained results indicate the enlargement of recessively homozygous genetic loads in the group of children with FS which may represent some kind of predisposition for expressivity of this type of seizures.