Figure 2. A: Array-CGH, cytogenetics, and FISH results. Ratio plot of high-resolution oligonucleotide array mapping of duplication 8q11.1–q12.1 (chr8:47655000-60101000) from the proband of Family 1. This technique evidenced a duplication of 13,1 Mb spanning from probe A_14_P107002 at 47.655 Mb to probe A_14_P128857 at 60.101 Mb. Because the probes contained in the Agilent 44B microarray slide do not cover the region ‘‘Gap_225’’ (3 Mb) from 8p11.1 to 8q11.1, between the centromere and probe A_14_P107002, we completed this interval by FISH with BAC clones. B: Cutout and ideogram of the normal chromosome 8 (left) and the duplicated (right) chromosome 8. Parental karyotypes were normal, suggesting that the abnormality was de novo. C: FISH with CEP8 (Vysis) showing the normal (arrowhead) and the dicentric duplicated chromosome 8 (arrow). In fact, the CEP 8 probe evidenced the presence of a second centromere or, most likely, a partial centromere because it appeared of reduced dimensions. D: After immunofluorescence with CENP-C, signals (green) are localized at the centromere of the normal chromosome 8 (arrowhead) but not at the second inactive centromere of the duplicated chromosome 8 (arrow). E: Dual-color FISH with BAC probes RP11-53M11, mapping to 8q11.23, and containing the gene SOX17 (green signal), and CEP8 (Vysis), specific for alphoid DNA of chromosome 8 centromere (red signals), showing a direct duplication of the segment 8q11.1–q12.1 (arrow); arrowhead indicates normal chromosome 8. 1356 HUMAN MUTATION, Vol. 31, No. 12, 1352–1359, 2010