Representative photograph of FISH signals for four patients (patients no. 3, 8, 10, and 13) in whom the FISH signals of the YAC 964c10 were observed to be split between the der(12) and the partner derivative chromosome. The left column (A, D, G, and J) shows the FISH signals of the YAC964c10, the middle column (B, E, H, and K) shows the signals of TEL exon 3 probe, and the right column (C, F, I, and L) shows the signals of P1 TEL probe in each patient. The small arrow indicates the normal chromosome 12, the large arrow indicates the derivative chromosome 12, and the arrowhead identifies the partner derivative chromosome. (A) FISH signals of the YAC964c10 were observed on the der(12), the der(8), and normal chromosome 12 in patient no. 3. (B and C) Signals of the TEL exon 3 and P1 TEL probes were observed only on the der(12) and normal chromosome 12. In patient no. 8, (D) FISH signals of the YAC964c10 were observed on the der(12), the der(6), and normal chromosome 12. (E) The TEL exon 3 probe was deleted from the der(12) and der(6). (F ) The signal of the P1 TEL was observed on the der(12) and normal chromosome 12. In patient no. 10, (G) FISH signals of the YAC964c10 were observed on the der(12), the der(9) (large arrowhead), mar1 (small arrowhead), and normal chromosome 12. (H and I) The signals of the TEL exon 3 and P1 TEL probes were observed only on the der(12), the mar1, and normal chromosome 12. In patient no. 13, (J) FISH signals of the YAC964c10 were observed on the der(12), the der(5), and normal chromosome 12. (K and L) Signals of the TEL exon 3 and P1 TEL probes were observed only on the der(5) and normal chromosome 12.