SMCs from patient 2. A. G-banded normal chromosome 13 homologues and SMCs (arrows). B. Array CGH plot showing gains of both proximal and distal 13q, with normal copy number in between. C. FISH using BACs RP11-408E5 from 13q12.11 (red signal) and RP11-63L17 from 13q34 (green signal) shows signal from both BACs on the large SMC (arrow), as well as both normal homologues of chromosome 13 (arrowheads). D. FISH using BACs RP11-347L8 from 13q12.13 (red signal) and RP11-63L17 (green) again confirms the presence of both proximal and distal 13q in the large SMC (arrow).