Chromothripsis Detectable in Small Supernumerary Marker Chromosomes (sSMC) Using Fluorescence In Situ Hybridization (FISH).

The formation of small supernumerary marker chromosomes (sSMC) still remains enigmatic. However, it is suggested that majority of all kinds of de novo sSMC (inverted duplication-, ring-, and centric-minute-shaped ones) are products of incomplete trisomic rescue during early embryogenesis. Recent work, based on molecular cytogenetics, suggests that these trisomic rescue events are going together with chromothripsis, directed against the supernumerary chromosome to be degraded. Here we present a protocol how to characterize so-called discontinuous sSMC by means of fluorescence in situ hybridization (FISH).