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Frank Tschentscher

Publications and source records attributed to Frank Tschentscher.

4 recordsLinked to original sources
PubMed2006

Genetic investigation of the TSPYL1 gene in sudden infant death syndrome.

BACKGROUND: Sudden infant death syndrome (SIDS) constitutes the most frequent cause of death in the postperinatal period in Germany. Recently, a lethal phenotype characterized by sudden infant death with dysgenesis of the testes syndrome (SIDDT) was identified to be caused by loss of function mutations in the TSPYL1 gene. PURPOSE: The study's purpose was to reveal a possible role of TSPYL1 in SIDS. METHODS: DNA samples of 126 SIDS cases and 261 controls were investigated. RESULTS: We found five sequence variations, each of them causing an amino acid substitution. No Hardy Weinberg disequilibrium and no significant difference in allele frequencies between patients and controls were observed for any variation. In one female patient a p.F366L amino acid polymorphism was found heterozygous, which could not be displayed in controls. A pathogenic implication of this substitution, which is conserved in primates and rodents, cannot be ruled out completely. Because SIDDT is the result of homozygous TSPYL1 mutations, this heterozygous exchange cannot solely explain the sudden death in this child. The reported mutation associated with SIDDT (457_458insG) was not detectable in our cohort. CONCLUSION: No association of sequence variations in the TSPYL1 gene and SIDS has been found in a German cohort. Genetic analysis of TSPYL1 seems to be of limited significance in the differential diagnosis of SIDS without dysgenesis of the testes.

Aged↗
PubMed2005

Protocols for ancient DNA typing.

Molecular analysis of fossil and archaeological remains has been established as a powerful tool in providing new insight in phylogenetic investigations. The overlapping set of molecular modifications and degradation that forensic samples share with archaeological specimen suggests the application of similar technical approaches to the respective biological material. Polymerase chain reaction is the molecular technique of choice for the retrieval of specimen deoxyribonucleic acid (DNA) molecules. Because of intrinsic sensitivity, potential contaminations from exogenous DNA sources must be monitored through the entire process by the introduction of multiple blank controls. Cloning and sequencing of polymerase chain reaction products often is the only way to discriminate between contaminations and endogenous sequences as well as to identify variable positions from nucleotide modifications/DNA polymerase errors. Phylogenetic analysis and investigations of the pattern of substitutions are an additional and necessary step to validate the retrieved sequence. Comparison with available related samples (modern or extinct) is critical to correctly validate the results and to avoid artifactual data.

Archaeology↗
PubMed2003

Tumor classification based on gene expression profiling shows that uveal melanomas with and without monosomy 3 represent two distinct entities.

Uveal melanoma is the most common intraocular malignancy. About 50% of patients die of metastases, which almost exclusively originate from primary tumors that have lost one chromosome 3 (monosomy 3). To gain insight into the biological mechanisms that underlie the various metastasizing potential of uveal melanoma, we have determined gene expression levels in 20 primary tumors using oligonucleotide microarrays containing 12500 probe sets. The expression measurements of those 7902 genes that were expressed in more than 10% of tumors were analyzed using two different statistical approaches. We used a modified Wilcoxon rank-sum test to identify genes differentially expressed between tumors with and without monosomy 3. Seven genes showed complete loss of expression in tumors with monosomy 3 but were expressed in tumors with disomy 3. Two of them, CHL1 and fls485, are located within or close to the uveal melanoma susceptibility locus UVM2 at 3p25. However, mutation analysis of both genes in eight tumors with monosomy 3 did not reveal structural or epigenetic alteration. To identify tumor classes, we performed unsupervised hierarchical cluster analysis; this approach separated uveal melanomas into two groups. We found that this classification is strikingly robust because, when tested by "resampling," the same grouping is obtained from 47 of 50 subsamples of genes. In clusterings of the three remaining subsamples, the grouping of only one tumor does not conform with the original classification. Excluding this tumor, cluster analyses of subsamples containing as few as 300 randomly chosen genes consistently result in the same classification, thus indicating that the difference between the two tumor classes is pervasive. Interestingly, all of the tumors in one of the groups have disomy 3, whereas all of the others have monosomy 3. Our findings suggest that there are two distinct entities of uveal melanoma that were previously unrecognized because they are not obviously distinguishable by clinicopathological features.

Chromosomes, Human, Pair 3↗