Detection of the aberrant constitutions of the chromosomes with FISH. FISH results on patient 1: A) The BAC-probe RP11-393E10 (10p13), green, which is deleted according to the SNP-array results, shows only one signal on the normal chromosome 10, confirming the deletion. RP11-24J20 (10p13), located distal from the deleted region, is present on the normal chromosome 10 and on the der(18). B) Besides present on the normal homologue, RP11-149I8 is located on der(10) and RP11-308K19 on der (18), both overlapping the respectively proximal and distal deletion breakpoints. C) A WCP of chromosome 10 shows four segments distributed over four chromosomes. D) A combined FISH of WCP 18 (red) and WCP 10 (green) shows the presence of chromosome 10 material at the interface of chromosome 18 and chromosome 1 on derivative chromosome 18. FISH results on patient 2: E) BAC-probes RP11-114H21 (green) (5q31.2) and RP11-729C24 (5q31.1) (red) demonstrate a direct insertion in derivative chromosome 9. F) Probe RP11-632L2 (13q31.3) (green) and probe RP11-80N14 (9q31.1) (red) show the insertion of part of chromosome 13 in derivative chromosome 9.