Detection of diagnostically critical, often hidden, anomalies in complex karyotypes of haematological disorders using multicolour fluorescence in situ hybridization.

Multicolour fluorescence in situ hybridization (M-FISH) simultaneously detects all 24 human chromosomes in unique fluorescent colours. The identification of diagnostically critical gene rearrangement(s) in complex karyotypes of haematological disorders continues to be a challenge. We present five cases in which t(9;11), complex t(8;22), t(12;21) and t(11;14) were detected primarily using M-FISH and were confirmed using locus-specific probes. We conclude that M-FISH can be effective in complete characterization of critical gene rearrangements in haematological disorders.