Mutations and promoter methylation status of NPM1 in myeloproliferative disorders.

We determined mutations and promoter methylation status of NPM1 using pyrosequencing in 199 samples of myeloid neoplasia including myeloproliferative disorders (MPD). The mutations were present in 4% of chronic myelomonocytic leukemia, but not in other MPD or myelodysplastic syndromes. Promoter methylation was rare, and was found in only three samples of MPD.