Partial triplication (7q) in a child with acute lymphoblastic leukemia demonstrated with conventional cytogenetics, PRINS, and chromosome painting

In this report we describe a partial triplication (7q) and other structural aberrations found in a child with acute lymphoblastic leukemia (ALL), and we demonstrate the importance of PRimed IN Situ labeling (PRINS) and chromosome painting as a support to banding analysis for the clarification of complex structural chromosome rearrangements. Initially, the der(7) was interpreted as der(7)t(1;7;7). However, PRINS and chromosomes painting showed that der(7) consisted entirely of chromosome 7 material. Further, a derivative chromosome interpreted by banding analysis as a der(17)t(?1;17) was shown to be der(17)t(13;17) by the newly developed PRINS painting technique.