Characterization of marker chromosomes by fish using microdissected probes from old carnoy-fixed cells: Report of two cases

We reported on two patients with ade novo marker chromosome of which the origins were successfully identified by FISH using microdissected probes. These probes were established by microdis-sections of extra chromosomal segments from Carnoy-fixed cells stored at −20°C for several years. Using these probes, we could verify partial 1q32 trisomy in a patient with 17p+ as well as partial 16q2 trisomy in another patient with 4p+.