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.
Felbor
Ute
U
Department of Human Genetics, University of Würzburg, Biozentrum, Am Hubland, Germany.
Rutschow
Désirée
D
Haaf
Thomas
T
Schmid
Michael
M
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