BACKGROUND: The Sorbs are an ethnic minority in Germany with putative genetic isolation, making the population interesting for disease mapping. A sample of N = 977 Sorbs is currently analysed in several genome-wide meta-analyses. Since genetic differences between populations are a major confounding factor in genetic meta-analyses, we compare the Sorbs with the German outbred population of the KORA F3 study (N = 1644) and other publically available European HapMap populations by population genetic means. We also aim to separate effects of over-sampling of families in the Sorbs sample from effects of genetic isolation and compare the power of genetic association studies between the samples. RESULTS: The degree of relatedness was significantly higher in the Sorbs. Principal components analysis revealed a west to east clustering of KORA individuals born in Germany, KORA individuals born in Poland or Czech Republic, Half-Sorbs (less than four Sorbian grandparents) and Full-Sorbs. The Sorbs cluster is nearest to the cluster of KORA individuals born in Poland. The number of rare SNPs is significantly higher in the Sorbs sample. FST between KORA and Sorbs is an order of magnitude higher than between different regions in Germany. Compared to the other populations, Sorbs show a higher proportion of individuals with runs of homozygosity between 2.5 Mb and 5 Mb. Linkage disequilibrium (LD) at longer range is also slightly increased but this has no effect on the power of association studies. Oversampling of families in the Sorbs sample causes detectable bias regarding higher FST values and higher LD but the effect is an order of magnitude smaller than the observed differences between KORA and Sorbs. Relatedness in the Sorbs also influenced the power of uncorrected association analyses. CONCLUSIONS: Sorbs show signs of genetic isolation which cannot be explained by over-sampling of relatives, but the effects are moderate in size. The Slavonic origin of the Sorbs is still genetically detectable. Regarding LD structure, a clear advantage for genome-wide association studies cannot be deduced. The significant amount of cryptic relatedness in the Sorbs sample results in inflated variances of Beta-estimators which should be considered in genetic association analyses.
- MeSH
- analýza hlavních komponent MeSH
- dospělí MeSH
- etnicita genetika MeSH
- fenotyp MeSH
- jednonukleotidový polymorfismus * MeSH
- lidé středního věku MeSH
- lidé MeSH
- populační genetika * MeSH
- populační skupiny genetika MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika etnologie MeSH
- Německo MeSH
- Polsko etnologie MeSH
Despite the independent segregation of genes encoding killer immunoglobulin-like receptor (KIR) and human leukocyte antigen (HLA), there is some evidence of some kind of co-evolution. Therefore, one could expect reduced KIR diversity within the HLA restricted population. A total of 41 unrelated individuals homozygous for ancestral HLA haplotype AH8.1 (HLA-A*0101-Cw*0701-B*0801-DRB1*0301-DQB1*0201) were genotyped for KIRs. Over all, 14 different genotypes were identified. The KIR genes and genotypes repertoire generally mirror the published frequencies in Caucasians. Except for KIR2DS4, all activating genes presented frequencies below 50%. KIR2DS5 was the least frequent among activating genes (17%), whereas KIR2DL5 (37%) among inhibitory ones. The most frequent (39%) was AA genotype. Twenty-two individuals (54%) had a copy of KIR haplotypes A and B (AB genotype), whereas three (7%) were homozygous for B (BB genotype). Nine of fourteen reported genotypes occurred only in one individual. Five genotypes were reported in less than twenty individuals worldwide and one genotype was reported so far only once. Conversely, the three most frequent genotypes account for 68% of all detected genotypes. The results show the unrestricted KIR diversity in this HLA uniform group and support the fact that the driving force for KIR evolution is not exclusively a major histocompatibility complex.
- MeSH
- DNA analýza genetika MeSH
- frekvence genu MeSH
- genotyp MeSH
- haplotypy genetika MeSH
- HLA antigeny genetika MeSH
- homozygot MeSH
- lidé MeSH
- polymerázová řetězová reakce MeSH
- populační skupiny genetika MeSH
- receptory KIR genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA MeSH
- HLA antigeny MeSH
- receptory KIR MeSH
The analysis of mtDNA haplogroup frequency in various populations is a tool for studying human history and population dynamics. The aim of this study is to map the frequency of major mtDNA haplogroups in 300 maternally unrelated individuals representing the Czech population of the central part of the Czech Republic. Eighteen polymorphic sites in the coding region of mtDNA were screened by PCR-RFLP to determine 11 mtDNA haplogroups and 5 subhaplogroups. The most frequent haplogroups were H (41%) and U (21%). Less frequent haplogroups were J and T, each with a frequency of 8%. Frequencies of other haplogroups (V, K, HV, W, preV, X, and I) did not exceed 5%. The results of our study reveal that the frequency of mtDNA haplogroups in the Czech population is similar to the frequencies obtained in other European countries, especially Poland, Germany, and Russia. On the contrary, significant differences in haplogroup frequency were found between the Czech and Finnish populations (haplogroups U, T, W) and populations from Bulgaria and Turkey (haplogroups H).
- MeSH
- běloši genetika MeSH
- haplotypy MeSH
- lidé MeSH
- mitochondriální DNA genetika MeSH
- polymerázová řetězová reakce MeSH
- polymorfismus délky restrikčních fragmentů MeSH
- populační dynamika MeSH
- populační genetika * MeSH
- populační skupiny genetika MeSH
- rozdělení chí kvadrát MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Československo MeSH
- Názvy látek
- mitochondriální DNA MeSH
The purpose of this study was to evaluate the homogeneity of Polish populations with respect to STRs chosen as core markers of the Polish Forensic National DNA Intelligence Database, and to provide reference allele frequencies and to explore the genetic interrelationship between Poland and neighboring countries. The allele frequency distribution of 10 STRs included in the SGMplus kit was analyzed among 2176 unrelated individuals from 6 regional Polish populations and among 4321 individuals from Germany (three samples), Austria, The Netherlands, Sweden, Czech Republic, Slovakia, Belarus, Ukraine and the Russian Federation (six samples). The statistical approach consisted of AMOVA, calculation of pairwise Rst values and analysis by multidimensional scaling. We found homogeneity of present day Poland and consistent differences between Polish and German populations which contrasted with relative similarities between Russian and German populations. These discrepancies between genetic and geographic distances were confirmed by analysis of an independent data set on Y chromosome STRs. Migrations of Goths, Viking influences, German settlements in the region of Volga river and/or forced population resettlements and other events related to World War II are the historic events which might have caused these finding.
- MeSH
- alely MeSH
- emigrace a imigrace MeSH
- frekvence genu MeSH
- genetické markery MeSH
- haplotypy MeSH
- heterozygot MeSH
- lidé MeSH
- lidský chromozom Y MeSH
- mikrosatelitní repetice genetika MeSH
- populační genetika * MeSH
- populační skupiny genetika MeSH
- soudní genetika * MeSH
- zeměpis MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Běloruská republika MeSH
- Česká republika MeSH
- Německo MeSH
- Nizozemsko MeSH
- Polsko MeSH
- Rakousko MeSH
- Rusko MeSH
- Slovenská republika MeSH
- Švédsko MeSH
- Ukrajina MeSH
- Názvy látek
- genetické markery MeSH
