Differential exon usage was observed in at least one exon of genes known to be involved in MDS pathophysiology (TP53 and EZH1), erythroid genes (ALAD, UROD and EPB42) and genes associated with cell cycle (AURKB and CRNDE) and RNA processing (RBM5, RBM25, PRPF40A and HNRNPD). The gene discussed is ALAD; the disease is myelodysplastic syndrome.