Thus, our studies have identified t(7;21)(p22;q22) as a rare but recurrent abnormality in MDS/AML, with the existence of alternative spliced forms of the RUNX1-USP42 transcript in different patients.     ///    Molecular analysis of 100 MDS and AML marrow specimens by RT-PCR did not reveal new cases with the RUNX1-USP42 fusion. 