title: Overrepresentation of small supernumerary marker chromosomes (sSMC) from chromosome 6 origin in cases with multiple sSMC.
abstract: Small supernumerary marker chromosomes (sSMC) in human are defined as additional centric derivatives smaller than chromosome 20. In the majority of the cases only one sSMC is present, leading to a more or less stable karyotype of 47,XX,+mar or 47,XY,+mar. In approximately 1.4% of sSMC cases two or up to seven markers of different chromosomal origin are reported. According to the literature a sSMC(6) was present in 33% of the patients with multiple sSMC while sSMC(6) are observed in <1% of cases with a single sSMC. Currently there is no explanation for this striking observation. Here we report on one more unique case with two sSMC, one derived from #5 and the other from #6. Using microdissection/reverse painting, subcentromere-specific multicolor FISH (subcenM-FISH) and multicolor banding (MCB), they could be described as min or r(6)(::p11.1 --> q11.1::) and r(5)(::p11.1 approximately 12 --> q10::q10 --> p11.1 approximately 12::), respectively. Reversed array CGH using the DNA of the microdissected sSMC as probe confirmed the FISH results and enabled the rapid mapping of the breakpoints.
authors.affiliation: Institut für Humangenetik und Anthropologie, D-07740 Jena, Germany. i8lith@mti.uni-jena.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Liehr
authors.forename: Heike
authors.initials: H
authors.lastname: Starke
authors.forename: Gabriele
authors.initials: G
authors.lastname: Senger
authors.forename: Cindy
authors.initials: C
authors.lastname: Melotte
authors.forename: Anja
authors.initials: A
authors.lastname: Weise
authors.forename: Joris Robert
authors.initials: JR
authors.lastname: Vermeesch
mesh_terms: D001483:Base Sequence; D002648:Child; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D025063:Chromosome Disorders / Q000235:genetics / Q000473:pathology; D020223:Chromosome Painting; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D005260:Female; D015894:Genome, Human; D006801:Humans; D007621:Karyotyping; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization / Q000379:methods