Mutations in NPM1 exon 12. (A) The mutated nucleotide and the predicted amino acid sequence in NPM1 exon 12 found in the present study are shown in comparison with the wild-type sequence. Type of mutation (mutations A, B, D) is designated according to a previous report. Four novel mutant variants are designated mutations G, H, I, and J. Red and blue indicate nucleotide insertions and termination codons, respectively. Green indicates the conserved residues in mutant NPM. Purple indicates putative residues of a consensus nuclear export signal (Lx[1-3]Vx[2-3]VxL; x indicates any residue). (B) Sequence results after cloning. Boxes indicate inserted 4-bp nucleotides. Arrowhead indicates the position of the insert at nucleotide 960 of the NPM1 gene.