Neocentric Small Supernumerary Marker Chromosomes by Chromosome



Among reported patients with small supernumerary marker chromosomes (sSMC), neocentric ones constitute one of the smallest groups. Neocentric sSMC have a centromeric constriction but no detectable alpha-satellite DNA. Thus, they are also called analphoid markers, which “carry newly derived centromeres (or ‘neocentromeres’) that are apparently formed within interstitial chromosomal sites that have not previously been known to express centromere function.” Still it is unclear how a neocentromere is really acquired and formed on an acentric fragment. In this chapter each chromosome is discussed, as is which and how many neocentric sSMC have been reported. A case report is provided for a neocentric sSMC(3).


Partial Trisomy Partial Monosomy Balance Situation Severe Clinical Consequence Small Supernumerary Marker Chromosome 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Institut für HumangenetikUniversitätsklinikum JenaJenaGermany

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