Molecular heterogeneity of the NUP98/HOXA9 fusion transcript in myelodysplastic syndromes associated with t(7;11)(p15;p15)..     ///    Each of them lacked the common 141 bp NUP98 exon which was contained in the NUP98/HOXA9 fusion transcripts detected in patient 2 and the reported AML cases.     ///    Patient 1 had two types of the novel NUP98/HOXA9 fusion transcripts.     ///    The invariant chimaeric NUP98/HOXA9 transcripts are a result of the fact that each breakpoint of the NUP98 and the corresponding breakpoint of the HOXA9 gene cluster occur within the same intron. 