Characterization of RUNX1 mutations in CMML patients. A: Genomic organization of RUNX1 gene at 21q22.12 and RUNX1 protein. Functional (i.e. RUNT and RUNXI [for RUNX Inhibitor domain], as defined by PFAM accession numbers PF00853 and PF08504, respectively) and motifs of the RUNX1 protein were positioned according to the SMART program http://smart.embl-heidelberg.de/. Nucleotide (cDNA level) and deduced aminoacid sequences of the RUNX1 protein are positioned above and below the corresponding protein, respectively. The genomic RUNX1 sequence of CMML 5 exhibited a mutation in the consensus splicing sequence of intron 3. B: Mutations of RUNX1. All mutations but one introduced an aberrant stop codon (cases 3, 6, 12, 15 and 87). Two missense mutations (cases 1 and 25) were also observed. The mutations are located with respect to the modified aminoacid of the RUNX1 protein. C: Representation of putative mutated RUNX1 proteins. According to the SMART program, all putative modified proteins have lost their RUNT and RUNXI domains.