Centromeric association of chromosome 16- and 18-derived microchromosomes.
A supernumerary C-band-positive microchromosome was observed in 88% of lymphocyte metaphases from a healthy 24-year-old female. Traditional cytogenetic analyses failed to determine the microchromosome's origin and structure. However, hybridization experiments with a panel of chromosome-specific alpha-satellite probes demonstrated that this microchromosome was derived from chromosome 16 and consisted mainly of transcriptionally inactive alpha-satellite DNA. The microchromosome closely associated with the centromere of most chromosomes. An even more pronounced centromeric association pattern was observed in a further microchromosome that was found to contain chromosome 18-specific alpha-satellite DNA. The latter microchromosome was detected in a female newborn affected with fetal alcohol syndrome. The two microchromosomes described here did not appear to bear major phenotypic risks.
Department of Human Genetics, University of Würzburg, Biozentrum, Am Hubland, Germany.
Ute
U
Felbor
Désirée
D
Rutschow
Thomas
T
Haaf
Michael
M
Schmid
D000328:Adult; D002503:Centromere / Q000235:genetics*; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D015342:DNA Probes / Q000235:genetics; D004276:DNA, Satellite; D005260:Female; D005347:Fibroblasts / Q000502:physiology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D007621:Karyotyping; D008214:Lymphocytes / Q000502:physiology; D008677:Metaphase / Q000235:genetics
D015342:DNA Probes; D004276:DNA, Satellite