FISH confirmation studies. A) Four different chromosome 12 abnormalities in patient #1 and the corresponding aCGH plot. Three duplication/deletion/duplication regions were confirmed by FISH: amplification of CCND2/12p13.32 (RP11-928N17) is denoted by a 7R/2G FISH pattern; deletion at 12p12.3 (1R/2G pattern) confirmed using the RP11-147E12 FISH probe which maps between PLCZ1 and PLEKHA5; and gain of SOX5 (RP11-34a16) at 12p12.1 with a 4~8R/2~ 4G patterns. B) Submicroscopic CNAs in a trisomy 8 patient #21. BAC aCGH plots for chromosomes 8, 1 and 21. Using the dye swap method, the top plot shows trisomy 8 (FISH confirmed in 82.5%), the middle plot shows a gain (duplication) of 1p21.3p12 confirmed by FISH (32%), and the bottom chromosome 21 plot shows a 344-kb RUNX1/21q22.12 deletion. The duplication was confirmed by FISH on metaphase cells using a 1p21 probe (RP11-96F24), which maps within the duplicated segment, labeled in red, and a control probe that maps to 1q24 (RP11-104L21) labeled in green. Arrow indicates tandem 1p duplication in the metaphase cell. The interphase cell shows three red signals and two green signals. Triple-color interphase FISH (lower right) confirms RUNX1 deletion in 10% of trisomy 8-positive cells. The chromosome 8 centromere probe is labeled in aqua (signals not arrowed), a control probe for distal 21q is labeled in green (white arrows), and the 180-kb RUN1 probe (dJ1107L6) is labeled in red. RUNX1 deletion was present in 10% of trisomy 8-posiitve cells.