In summary, the exclusion of MDS in DS from patient series of primary MDS decreases the number of cases diagnosed as RAEB-T by approximately half, and substantially reduces the proportion of patients with trisomy 8 as sole abnormality. Considering that the great majority of children with myeloid leukemia in DS are under 5 years of age, exclusion of MDS in DS from pediatric MDS cohorts will result in an even greater reduction of advanced MDS in this age group.
Reporting incidence figures in rare heterogeneous entities will require careful description of inclusion criteria.