Prenatal molecular cytogenetic diagnosis of partial tetrasomy 10p due to neocentromere formation in an inversion duplication analphoid marker chromosome
| Autor: | Nataline B. Kardon, Kurt Hirschhorn, James Tepperberg, S. Fallet, M.S. Magid, T.M. Dunn, Peter Papenhausen, Brynn Levy, Peter E. Warburton |
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| Rok vydání: | 2001 |
| Předmět: |
Adult
Genetic Markers medicine.medical_specialty Neocentromere Marker chromosome Pregnancy High-Risk Centromere Aneuploidy Chromosome Disorders Biology DNA Satellite Chromosome Painting Pregnancy Gene Duplication Prenatal Diagnosis Gene duplication Genetics medicine Humans Molecular Biology Genetics (clinical) Chromosome Aberrations Chromosomes Human Pair 10 Cytogenetics medicine.disease Molecular biology Chromosome Banding Genetic marker Karyotyping Tetrasomy Chromosome Inversion Amniocentesis Female DNA Probes Maternal Age |
| Zdroj: | Cytogenetics and cell genetics. 91(1-4) |
| ISSN: | 0301-0171 |
| Popis: | Neocentromeres are fully functional centromeres found on rearranged or marker chromosomes that have separated from endogenous centromeres. Neocentromeres often result in partial tri- or tetrasomy because their formation confers mitotic stability to acentric chromosome fragments that would normally be lost. We describe the prenatal identification and characterization of a de novo supernumerary marker chromosome (SMC) containing a neocentromere in a 20-wk fetus by the combined use of comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). GTG-banding of fetal metaphases revealed a 47,XY,+mar karyotype in 100% of cultured amniocytes; parental karyotypes were both normal. Although sequential tricolor FISH using chromosome-specific painting probes identified a chromosome 10 origin of the marker, a complete panel of chromosome-specific centromeric satellite DNA probes failed to hybridize to any portion of the marker. The presence of a neocentromere on the marker chromosome was confirmed by the absence of hybridization of an all-human-centromere alpha-satellite DNA probe, which hybridizes to all normal centromeres, and the presence of centromere protein (CENP)-C, which is associated specifically with active kinetochores. Based on CGH analysis and FISH with a chromosome 10p subtelomeric probe, the marker was found to be an inversion duplication of the distal portion of chromosome 10p. Thus, the proband's karyotype was 47,XY,+inv dup(10)(pter--p14 approximately 15::p14 approximately 15--neo--pter), which is the first report of partial tetrasomy 10p resulting from an analphoid marker chromosome with a neocentromere. This study illustrates the use of several molecular strategies in distinguishing centric alphoid markers from neocentric analphoid markers. |
| Databáze: | OpenAIRE |
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