Characterization of multiple marker chromosomes in patient 4 by array CGH and FISH. A. Chromosome plots showing pericentromeric gains of 1p, 4q, 7p, and 11q detected by array CGH. B. – D. G-banded and corresponding destained FISH images of the marker chromosomes. B. FISH using BAC RP11-601I15 from 4q12 (orange) and a chromosome 11 alpha satellite probe (green), demonstrating the presence of both chromosome 11 centromere and 4q12 material in the largest SMC (arrow). One normal homologue of chromosome 11 (white arrowhead) and one normal homologue of chromosome 4 (gray arrowhead) are also shown. C. FISH using BAC RP11-1324A7 from 7p11.1, demonstrating signal on a marker chromosome (arrow) and one of the normal chromosome 7 homologues (arrowhead). D. FISH using BAC RP11-527D19 from 1p12, demonstrating signal on a marker chromosome (arrow) and one of the normal chromosome 1 homologues (arrowhead). E. FISH using an X alpha satellite probe (green) and a probe containing the steroid sulfatase (STS) gene (orange). The smallest marker chromosome contains X centromere material, but not STS (arrow). One normal X chromosome homologue is also shown (arrowhead).