Frequency and distribution of cytogenetic abnormalities in patients exhibiting at least one abnormality. Excluding the WHO category “AML with recurrent genetic abnormalities”1 (A, t-AML n = 78, B, de novo AML, n = 698; definition “complex” according to Döhner et al28 and of “monosomal karyotype” according to Breems et al40 ).