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R Szibor

Publications and source records attributed to R Szibor.

At least 37 records · Page 2Linked to original sources
PubMed1999

Validation of the HumDXS6807 short tandem repeat polymorphism for forensic application.

This paper presents sequence and population genetic data of the HumDXS6807 short tandem repeat (also known as CHLC.GATA52B03) which is a tetranucleotide repeat polymorphism representing seven alleles of 251-275 bp in length. HumDXS6807 is located at Xpter-Xp22.2, i.e., at a genetic distance of more than 87 and 151 cM from the well-known markers HumARA and HumHPRTB, respectively. Kinship tests in 157 family trios revealed a typical X-linked codominant inheritance; mutations were not found. Population genetic data were obtained by analyzing a Caucasian population sample comprising 308 females and 209 males: polymorphism information content (PIC) = 0.640; Heterozygosity (Het) = 0.668; Mean exclusion chance (MEC) = 0.414. The HumDXS6807 allele distribution met the Hardy-Weinberg expectations.

DNA↗
PubMed1999

No microsatellite instability, but frequent LOH in liposarcomas.

To evaluate the significance of microsatellite instability (MI) and loss of heterozygosity (LOH) in the development of different histological subgroups of liposarcomas, we examined 28 tissue-samples from 21 patients and the corresponding non-neoplastic reference tissues. We investigated nine microsatellite loci and detected no MI. LOH for at least one marker was observed in 11 of 28 tumours (39%). Widespread allelic losses were a common characteristic of pleomorphic liposarcomas. Well-differentiated variants did not show LOH (p<0.003). Our findings support the idea that liposarcoma subgroups are defined by different spectra of genetic alterations. Inefficient DNA mismatch repair does not seem to be involved in the oncogenesis of liposarcomas.

DNA Repair↗
PubMed1998

Population genetic data of the STR HumD3S1358 in two regions of Germany.

This report gives the results of two population studies on HumD3S1358 from a northern and a southern region of Germany. The numbers of unrelated individuals were 326 and 666, respectively and seven main alleles, three rare allelic variants and 29 different genotypes were encountered. No significant statistical differences were seen between the northern and southern populations. The HumD3S1358 allele distributions were in agreement with Hardy-Weinberg expectations and two mutations were found in 780 meiotic events.

Adult↗
PubMed1998

mtDNA depletion and impairment of mitochondrial function in a case of a multisystem disorder including severe myopathy.

The ratio of mtDNA and a nuclear reference gene was estimated by Southern blotting in the skeletal muscle DNA of a 3-year-old girl who suffered from congenital brain damage, focal epilepsy, hepatomegaly, malabsorption syndrome and severe myopathy. The signal ratio of mtDNA versus 18S rDNA was 22% of the mean value obtained from controls. No major deletions or insertions were found and the MERRF, MELAS and NARP mutations were ruled out. Mitochondrial DNA-encoded enzyme activities and mitochondrial respiration were reduced. The analysis of the NAD(P)H and flavoprotein redox states of intact fibres revealed the presence of mitochondrial dysfunction. In tissue sections a moderate elevation of type I and type II fibre diameter variation was detected, aberrant NADH- and succinate dehydrogenase staining and some ragged red fibres. This suggested that a mitochondrial disorder caused by a decrease in the amount of intact wild-type mtDNA was responsible for the severe myopathy.

Abnormalities, Multiple↗
PubMed1997

Mitochondrial D-loop 3' (CA)n repeat polymorphism: optimization of analysis and population data.

We report a dinucleotide repeat polymorphism in the 3' area of the mitochondrial control region. The fragments obtained using a new primer set could be reliably separated by polyacrylamide gel electrophoresis (PAGE) using nondenaturing gels. A total of five alleles [(CA)3 to (CA)7] were detected on silver-stained gels. The 90 bp product corresponds to allele 5. Samples from one African and three European populations were characterized. Significant differences could be demonstrated as to the incidence of single alleles and allele distributions in different populations. These differences were found between the three European and one African Bantu population. For specific forensic questions the mitochondrial CA repeat is well suited. Gene diversities in populations of Germany, Hungary, the Russian Federation and Cameroon were 0.36, 0.40, 0.34, 0.52, respectively.

Africa↗
PubMed1992

Prevalence of cystic fibrosis mutations in the East German population.

A representative multicenter cystic fibrosis (CF) mutation analysis on about half of all known cystic fibrosis patients of the 5 East German Länder is reported. Analyses for 17 mutations, among them Delta F508, R553X, G542X, S549R,N,I, G551D, S1255X, R347P,H, and Y122X, were performed. As expected, the delta F508 mutation in exon 10 of the CFTR gene is the major gene alteration causing CF in our patients. However, in comparison to studies from Western Germany, a significantly lower percentage of just over 60% is found in our patients, resembling data obtained from slavonic populations. The severe phenotype of cystic fibrosis is most frequently associated with homozygosity for the delta F508 mutation. No particular allele association could be found with the intermediate and mild phenotypes of this disease. The next most frequent of the investigated mutations is R553X (13.3% of non-delta F chromosomes) followed by R347P (9.2%) and G542X (4.4%).

Cystic Fibrosis↗
PubMed1991

[The polymerase chain reaction PCR and its use in genetic diagnosis].

In genomic diagnosis the ensemble of techniques has been recently expanded by the powerful method of the polymerase chain reaction (PCR). Using pairs of synthetic oligonucleotides for priming of synthesis and a thermoresistant DNA polymerase a millionfold amplification of target DNA sequences from patients provides DNA fragments for following investigations such as electrophoresis. The paper presents some examples of PCR application for diagnosis in cystic fibrosis and Duchenne muscular dystrophy.

Cystic Fibrosis↗
PubMed1990

First analysis of the F508 deletion in cystic fibrosis patients from the GDR.

Cystic fibrosis (CF) patients (n = 157) from the GDR were analysed for the occurrence of the recently discovered 3bp deletion causing CF. About 50% of all investigated patients were homozygotes and about 30% heterozygotes for this deletion. Of the analysed CF chromosomes from these patients, 62% carry the deletion, which is in strong linkage disequilibrium with the KM19 restriction fragment length polymorphism allele 2 and the 1/2 XV2c/KM19 haplotype.

Chromosome Deletion↗
PubMed1989

[Attempt at diagnosis of hereditary spherocytosis using the ionophore valinomycin].

On the basis of former observations that erythrocytes of patients with hereditary spherocytosis (HS) exhibit a slighter K+ efflux under the influence of valinomycin and a diminished shrinking, the attempt was made to use this phenomenon in routine diagnostics. In pair comparison the findings already known could be proved impressively. However, obligatory limiting values which make it possible to dispense with giving statements of comparison could not be established. In this report the test is of limited value for haematological diagnostics.

Erythrocytes↗
PubMed1988

Different numbers of maternal and paternal siblings of cystic fibrosis patients.

When 458 parents of children suffering from cystic fibrosis (CF) from all over the German Democratic Republic were interviewed to determine the number of their siblings, it was found that the maternal families had a total of 1369 children and the paternal, 1220. While the fathers of CF patients tended to originate from families with one or two children, more mothers than fathers came from families with three to twelve children (P = 0.01). The average number of children in the maternal families was 2.99; in the paternal families, only 2.66. To rule out any methodological errors, sibs of mothers and fathers of various control groups were studied. We found that the number of siblings in these groups was balanced. The differences in our findings are probably due to CF heterozygosity. The underlying mechanism is unknown.

Adult↗