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 struc tural aberrations found in a child with acute lymphoblastic leukemia ( ALL), and we demonstrate the importance of PRimed IN Situ labeling (PR INS) and chromosome painting as a support to banding analysis for the clarification of complex structural chromosome rearrangements. initial ly the der(7) wets interpreted as der(7)t(1;7;7). However, PRINS and c hromosomes painting showed that der(7) consisted entirely of chromosom e 7 material. Further, a derivative chromosome interpreted by banding analysis as a der(17)t(?1;17) was shown to be der(17)t?1;17) by the ne wly developed PRINS painting technique.