Overrepresentation of small supernumerary marker chromosomes (sSMC) from chromosome 6 origin in cases with multiple sSMC.
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.
Liehr
Thomas
T
Institut für Humangenetik und Anthropologie, D-07740 Jena, Germany. i8lith@mti.uni-jena.de
Starke
Heike
H
Senger
Gabriele
G
Melotte
Cindy
C
Weise
Anja
A
Vermeesch
Joris Robert
JR
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