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Chromosome 18 replaced by two ring chromosomes of chromosome 18 origin

Item Type:Article
Title:Chromosome 18 replaced by two ring chromosomes of chromosome 18 origin
Creators Name:Miller, K. and Pabst, B. and Ritter, H. and Nuernberg, P. and Siebert, R. and Schmidtke, J. and Arslan-Kirchner, M.
Abstract:We here describe the first example of the replacement of an autosome by two ring chromosomes originating from the missing chromosome, presented in a patient with a single chromosome 18 and two additional ring chromosomes. Detailed fluorescence in situ hybridization (FISH) analysis revealed the chromosome 18 origin of both ring chromosomes and characterized the small and the large ring chromosome as derivatives of the short and long arm of chromosome 18, respectively. The loss of subtelomeric regions of the short and the long arm of chromosome 18 in the ring chromosomes was confirmed by FISH studies. Molecular studies showed the exclusive presence of the paternal alleles for microsatellite markers located distal to the short and long arm loci D18S843 and D18S474, respectively. This indicates the maternal origin of both rings and provides evidence for substantial deletions of the distal parts of both arms of chromosome 18 in the ring chromosomes. The dysmorphic features of the patient can be explained by these deletions in both chromosome arms, as the clinical findings partly overlap with observations in 18p- and 18q-syndrome and are similar to some cases of ring chromosome 18. Centromere misdivision is suggested as one mechanism involved in the formation of the ring chromosomes.
Keywords:Alleles, Centromere, Fluorescence In Situ Hybridization, Genetic Markers, Genotype, Karyotyping, Microsatellite Repeats, Multiple Abnormalities, Pair 18 Human Chromosomes, Ring Chromosomes, Syndrome
Source:Human Genetics
Page Range:343-347
Date:April 2003
Official Publication:https://doi.org/10.1007/s00439-002-0885-1
PubMed:View item in PubMed

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