Characterization of a complex rearrangement of a chromosome 20 by FISH and array CGH

We report on a patient with a Complex Chromosomal Rearrangement (CCR) of a chromosome 20. CCRs are structural rearrangements involving three or more chromosomes or having more than two breakpoints; congenital CCRs compatible with life are a rare finding in humans. The rearranged chromosome 20 was characterized by array Comparative Genomic Hybridization (array CGH), and Fluorescent In Situ Hybridization (FISH). The combination of these two techniques made it possible to precisely define the rearrangement and showed a very unusual architecture, with segments deleted, duplicated, inverted, and shifted. Potential mechanisms generating such a complex rearrangement and candidate genes responsible for the phenotype are discussed.