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Biomedical subjects

J Schmidtke

Publications and source records attributed to J Schmidtke.

At least 109 records · Page 6Linked to original sources
PubMed1990

The rapid molecular genetic diagnosis of cystic fibrosis by polymerase chain reaction: an experience report.

The authors report their experience with about two thousand DNA amplifications by polymerase chain reaction (PCR) in prenatal diagnosis of cystic fibrosis. The method is demonstrated on examples of diagnostic informativity and prenatal diagnosis examination in a family at 1 in 4 risk of the disease using closely CF-linked diagnostic polymorphisms: J3.11/MspI, MetH/MspI, CS7/HhaI, KM19/PstI, Mp6-d9/MspI and XV2c/TaqI, PCR methodology and safety precautions are discussed.

Cystic Fibrosis↗
PubMed1990

Cystic fibrosis marker testing in Bohemia with polymerase chain reaction.

Conditions for assessing KM-19 probe detected by Pst-1 restriction fragment length polymorphism (RFLP) by means of polymerase chain reaction were provided. Computer controlled mechanical arm with waterbaths and cloned heat-stable DNA polymerase was used. Results of KM-19 allelic frequencies on 90 cystic fibrosis chromosomes are presented. Allele two frequency was -0.833.

Alleles↗
PubMed1989

Polymerase chain reaction: replication errors and reliability of gene diagnosis.

The impact of replication errors on the reliability of polymerase chain reaction (PCR) data is studied theoretically. Practical applications of our results to RFLP analysis and oligonucleotide probing confirm that for practical purposes replication errors can be neglected if a large number of starting templates (e.g. 100,000) is being used. For single locus analysis in single cells, however, the probability of false diagnosis due to such errors is of the order of 1 percent.

DNA Replication↗
PubMed1989

A search for restriction fragment length polymorphism on the human Y chromosome.

A systematic search for restriction fragment length polymorphisms (RFLPs) on the human Y chromosome was performed. DNA samples from 16-34 individuals were screened with five restriction enzymes and 12 Y-chromosomal probes, 3 of which detect lowly repetitive sequences and 9 of which are apparently single copy in genomic DNA. None of the single-copy probes revealed any variation. The repetitive sequence probe p21A1 (DYZ?) revealed a TaqI RFLP with q = 0.05. The frequency of fixed point mutations in Y-chromosomal DNA outside the pseudoautosomal region is probably less than 1 in 18,000 bp.

Blotting, Southern↗
PubMed1989

Diagnosis of genetic disease using recombinant DNA. Second edition.

Recombinant DNA methodology has greatly increased our knowledge of the molecular pathology of the human genome at the same time as providing the means to diagnose inherited disease at the DNA level. Direct detection and analysis of a range of genetic defects are now possible using cloned gene or oligonucleotide probes or by direct sequencing of the disease gene(s). In addition, the use of restriction fragment length polymorphism (RFLPs) within and around these genes as indirect genetic markers has now potentiated the tracking of disease alleles in affected pedigrees in cases where direct analysis was not feasible. RFLPs associated with linked anonymous segments may also be used not only to diagnose hitherto undetectable disease states, but also for chromosomal localization of the loci responsible. We present here an up-to date list of reports describing both the direct and the indirect analysis/diagnosis of human inherited disease, which is intended to serve as a guide to current molecular genetic approaches in diagnostic medicine.

DNA, Recombinant↗
PubMed1989

Characterization of rearranged Y chromosomes in human testicular tumor cell lines.

Cytogenetic analysis of four cell lines established from two different human testicular tumors revealed rearranged or missing Y chromosomes. Southern blot analysis and in situ hybridization with different Y-derived human DNA sequences revealed the existence of Y chromosomal material even in a line without a cytogenetically visible Y chromosome and clarified the composition of Y marker chromosomes.

Base Sequence↗
PubMed1989

A comprehensive list of cloned human DNA sequences.

A list of DNA sequences cloned from the human genome is presented. Intended as a guide to clone availability, this list includes published reports of cDNA, genomic and synthetic clones comprising gene and pseudogene sequences, uncharacterised DNA segments and repetitive DNA elements.

Base Sequence↗
PubMed1989

[DNA diagnosis of monogene hereditary diseases exemplified by phenylketonuria and mucoviscidosis].

In 170 inherited diseases there exists the possibility for diagnosis at the DNA level. Using phenylketonuria (PKU) and cystic fibrosis (CF) as examples we demonstrate the capability of direct and indirect DNA-diagnosis through the use of DNA markers and allelespecific oligonucleotide hybridization respectively. In 88% of our PKU-patients and in 98% of the CF-patients DNA linkage analysis and therefore prenatal diagnosis on the DNA level can be carried out in affected families. The reliability of DNA-diagnosis is 99.0% for PKU and between 96.0-99.99% for CF depending on where the DNA-markers are localized. In contrast to CF, the PKU gene has been isolated and distinct mutations within the phenylalanine hydroxylase gene have been characterized. There is evidence for a correlation between genotype and clinical and biochemical phenotype. Also in CF it is indicated that certain DNA haplotypes correlate with the severity of the disease: less frequent haplotypes seem to be more often associated with a milder course than haplotype "B/B" which represents 85% of the CF chromosomes. Therefore DNA diagnostic methods not only make a major contribution to improved genetic counseling but also offer the possibility for a better future understanding of the heterogeneity of genetic diseases.

Cystic Fibrosis↗
PubMed1989

[Genome analysis].

So far, about 1% of human genes have been molecularly cloned and chromosomally mapped. Thus only a small proportion of the hereditary disorders of man are accessible to molecular genetic analysis. Such an analysis, however, is a prerequisite for the development of diagnostic and therapeutic measures.

Animals↗
PubMed1988

Prenatal diagnosis of cystic fibrosis using linked DNA probes.

This paper presents data collected in Europe on 107 prenatal diagnoses of cystic fibrosis (CF) using linked DNA markers. To date, 38 children have been born without CF, as predicted, demonstrating the present rapid move from research to clinical genetic service.

Adult↗
PubMed1988

Linkage of the DNA-segment D7S13 (pB79a) with the cystic fibrosis locus.

A map distance of 2.9 cM between D7S13 (pB79a) and the cystic fibrosis (CF) locus was obtained from the analysis of 13 informative families with a history of CF. This result is based solely on the HindIII restriction fragment length polymorphism (HindIII-RFLP) at D7S13, since the interpretation of the MspI-RFLP at this locus was found to be unreliable.

Cystic Fibrosis↗