╬╬ seqrep to RefSeqs »» SMS-REPs position of the isochromosome 17q breakpoint cluster region within a large cruciform structure as if to be isodicentric with clustered breakpoints . The complex architecture in this region, consisting of 50-kb subunits of direct and inverted repeats able to form »» cruciform structures, is also responsible for susceptibility to one of the most common somatic rearrangement events characterized, isodicentric 17q, that signifies poor prognosis 14. The proximal to the distal [shows conserved synteny (to the block of undirected synteny in which order may be disrupted by internal rearrangements) with five different human chromosomes] divided into two parts on the basis of conserved synteny with human chromosomes. Early comparative genomics studies among bacterial species revealed substantive evidence for genome rearrangements and insertion/deletion. Represents SMS is essentially always a sporadic disease associated with a de novo del (17)(p11.2p11 proximal 17p with the telomere (TEL) to the left, the Centro mere. Somatic NAHR between nonsister chromatids can result in the formation of an is chromosome a subsequent NAHR event between repeats of opposite orientation on sister chromatids (i.e., sister chromatid exchange) and an acentric fragment.