Miroslav Soták

Contemporary paternal genetic landscape of Polish and German populations: from early medieval Slavic expansion to post-World War II resettlements

Homogeneous Proto-Slavic genetic substrate and/or extensive mixing after World War II were suggested to explain homogeneity of contemporary Polish paternal lineages. Alternatively, Polish local populations might have displayed pre-war genetic heterogeneity owing to genetic drift and/or gene flow with neighbouring populations. Although sharp genetic discontinuity along the political border between Poland and Germany indisputably results from war-mediated resettlements and homogenisation, it remained unknown whether Y-chromosomal diversity in ethnically/linguistically defined populations was clinal or discontinuous before the war. In order to answer these questions and elucidate early Slavic migrations, 1156 individuals from several Slavic and German populations were analysed, including Polish pre-war regional populations and an autochthonous Slavic population from Germany. Y chromosomes were assigned to 39 haplogroups and genotyped for 19 STRs. Genetic distances revealed similar degree of differentiation of Slavic-speaking pre-war populations from German populations irrespective of duration and intensity of contacts with German speakers. Admixture estimates showed minor Slavic paternal ancestry (∼20%) in modern eastern Germans and hardly detectable German paternal ancestry in Slavs neighbouring German populations for centuries. BATWING analysis of isolated Slavic populations revealed that their divergence was preceded by rapid demographic growth, undermining theory that Slavic expansion was primarily linguistic rather than population spread. Polish pre-war regional populations showed within-group heterogeneity and lower STR variation within R-M17 subclades compared with modern populations, which might have been homogenised by war resettlements. Our results suggest that genetic studies on early human history in the Vistula and Oder basins should rely on reconstructed pre-war rather than modern populations.

Association of the FTO rs9939609 polymorphism with obesity in Roma/Gypsy population

The rs9939609 SNP located in the first intron of the fat mass and obesity associated gene (FTO) has been found to be associated with common obesity mainly in populations of European descent. The Roma/Gypsy population as an ethnic minority of Asian Indian origin is well known for its adverse health status with a high prevalence of obesity. The main aim of this study was to examine the contribution of the rs9939609 FTO polymorphism to the high prevalence of obesity in the Roma/Gypsy population. Following a number of anthropometric measurements, the FTO rs9939609 polymorphism was genotyped in 312 Roma/Gypsy individuals. We observed significant differences in body mass index (BMI), waist circumference, and waist-to-hip ratio between different genotypes (P = 0.003, P = 0.012, and P = 0.03, respectively). The waist circumference in the subjects with AA genotype was about 7.1 cm larger than in those with TT genotypes (P = 0.005). However, the strongest association of minor allele A of the rs9939609 FTO polymorphism was found with BMI (odds ratio, 1.55; 95% confidence interval, 1.129-2.128; P = 0.007), even after adjusting for age, sex, and smoking status. This study provides the first report of allele and genotype frequencies for the rs9939609 polymorphism and also the first evidence of the association of the FTO variant with obesity in the Roma/Gypsy population.

Allele frequencies and population data for 11 Y-chromosome STRs in samples from Eastern Slovakia

Haplotype data of 11 Y-STR loci (DYS391, DYS389I, DYS439, DYS389II, DYS438, DYS437, DYS19, DYS392, DYS393, DYS390 and DYS385) was obtained from 629 Slovak Caucasian men living in Eastern Slovakia. A total of 474 haplotypes were identified, of which 395 were unique. The haplotype diversity value was 0.9982. Pairwise haplotype distances showed that the Eastern Slovak Caucasian population is not significantly different from the Slavs populations and is separated from the Balkan nations and the German speaking populations.

Genetic variation analysis of 15 autosomal STR loci in Eastern Slovak Caucasian and Romany (Gypsy) population

The genotype polymorphism studies were carried out on two different populations: Eastern Slovak Caucasian (138) and Romany (Gypsy) (138), both from the town of Presov, at 15 highly polymorphic short tandem repeats (STRs) loci. The selected kit PowerPlex 16 system (Promega) included amelogenin, two penta-nucleotide repeats and 13 tetra-nucleotide repeats. The comparison of the allele frequencies between Eastern Slovak Caucasians and Romanies has shown significant differences in the majority of the focused loci. The P-values of exact test for Hardy-Weinberg equilibrium probabilities, observed and expected heterozygosity, matching probability, power of discrimination and exclusion, polymorphic information content, typical paternity index, genetic diversity and the other population-genetic indices were calculated.

Unique frequencies of HFE gene variants in Roma/Gypsies

The aim of this study was to assess the frequencies of three hemochromatosis gene (HFE) mutations in ethnic Roma/Gypsies in Slovakia. A cohort of 367 individuals representing general population and not preselected for health status was genotyped by TaqMan real-time PCR assay for C282Y, H63D and S65C mutations in HFE gene. A unique genetic profile was revealed: C282Y is found in the highest frequency of all Central European countries (4.90%), while the frequency of H63D mutation (4.09%) is lower than any reported in Europe so far. S65C mutation was not present in the cohort. These mutation frequencies can be explained rather by gene influx and genetic isolation than by genetic inheritance from a former Roma/Gypsy homeland.

Comparison of Y-STR polymorphisms in three different Slovak population groups

Eleven Y-chromosomal microsatellite loci included in the Powerplex Y multiplex kit were analyzed in different Slovak population samples: Habans (n = 39), Romanies (n = 100) and Slovak Caucasian (n = 148) individuals, respectively, from different regions of Slovakia. The analysis of molecular variance between populations indicated that 89.27% of the haplotypic variations were found within populations and only 10.72% between populations (Fst = 0.1027; p = 0.0000). The haplotype diversities were ranging from 0.9258 to 0.9978, and indicated a high potential for differentiating between male individuals. The study reports differences in allele frequencies between the Romanies, Habans and Slovak Caucasian men. Selected loci showed that both the Romany and Haban population belonged to endogamous and relatively small founder population groups, which developed in relatively reproductive isolated groups surrounded by the Slovak Caucasian population.

Hemochromatosis gene mutations in the general population of Slovakia

This is an epidemiologic study of the Slovak population with the aim of determining the frequencies of three hemochromatosis gene (HFE) variants C282Y, H63D and S65C known to be associated with manifestation of hereditary hemochromatosis and to assess deviations of these frequencies from those reported elsewhere. Mutations were detected in 359 ethnic Slovaks by real-time PCR assay based on TaqMan technology. The allelic frequencies were 4.03% for C282Y, 12.67% for H63D and 1.25% for S65C mutation. We observed 0.28% of C282Y/C282Y homozygotes, 3.34% H63D/H63D homozygotes, 0.84% of C282Y/H63D compound heterozygotes and 0.56% of H63D/S65C compound heterozygotes. This is the first time the frequencies of H63D and S65C mutations have been reported in the general population in Slovakia. The observed allelic frequencies are consistent with the previous studies of Slavic and Central European populations.