title: Independent post-zygotic breaks of a dicentric chromosome result in mosaicism for an inverted duplication deletion 9p and terminal deletion 9p.
abstract: Mosaicism with two cell lines having different rearrangements of the same chromosome is rare. Only a few cases of mosaicism have been described in association with chromosomal inverted duplication deletion (inv dup del) rearrangements. A well-established mechanism of formation of inv dup del rearrangements involves a dicentric intermediate, which undergoes breakage during cell division, generating cells with either an inv dup del or a simple deletion. A patient with developmental delay and dysmorphic features was found to carry two cell lines with rearrangements of 9p: an inv dup del 9p and a terminal deletion 9p. Microarray and FISH analysis showed that these cell lines do not constitute the reciprocal products of a single dicentric breakage event. We propose that independent post-zygotic breaks of a dicentric chromosome as a likely mechanism leading to the generation of the observed cell lines. The post-zygotic origin of the inv dup del rearrangements and the associated mosaicism can be a more frequent phenomenon than currently appreciated. Therefore, genotype-phenotype correlations in the inv dup del rearrangements need to take into account the possible presence of other abnormal cell lines during early development.
authors: Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada. ksbartusiak@cw.bc.ca
authors: Kamilla
authors: K
authors: Schlade-Bartusiak
authors: Tracy
authors: T
authors: Tucker
authors: Holly
authors: H
authors: Safavi
authors: Janet
authors: J
authors: Livingston
authors: Margot I
authors: MI
authors: van Allen
authors: Patrice
authors: P
authors: Eydoux
authors: Linlea
authors: L
authors: Armstrong
mesh_terms: D002872:Chromosome Deletion; D025063:Chromosome Disorders / Q000235:genetics*; D007446:Chromosome Inversion; D002874:Chromosome Mapping; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D005260:Female; D020440:Gene Duplication; D015321:Gene Rearrangement; D056726:Genetic Association Studies; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D046228:Microarray Analysis; D009030:Mosaicism