We screened 45 patients with chronic myelomonocytic leukemia (n = 39 patients, including seven with transformed-acute myeloid leukemia), MDS/MPN unclassifiable (n = 5), and atypical BCR-ABL1-negative CML (n = 1) for mutations in ASXL1, CBL, NRAS, and TET2 genes by molecular genetics including a sensitive next-generation sequencing (NGS) technique.
We investigated 15,542 patients with suspected BCR-ABL1- negative myeloproliferative or myelodysplastic/myeloproliferative neoplasm (including 359 chronic myelomonocytic leukemia) by a molecular marker set.
Although the clinical, morphologic, and laboratory findings vary along a continuum from MDS to MPN, distinctive features are usually present that allow assignment of most of the cases to 1 of 3 distinct subtypes recognized by the 2008 World Health Organization (WHO) classification: chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia, BCR-ABL(-)(aCML, BCR-ABL1(-)), and juvenile myelomonocytic leukemia (JMML).
History, physical examination and laboratory findings were in favor of juvenile myelomonocytic leukemia in both the cases, but reverse transcriptase polymerase chain reaction (RT-PCR) detected b2a2 and b3a2 transcript of p210 bcr-abl protein characteristic of major BCR breakpoint.
Chromosomal deletions of band 13q14 occur recurrently in BCR/ABL negative chronic myeloproliferative disorders (CMPD), including myelosclerosis with myeloid metaplasia (MMM), polycythemia vera (PV), essential thrombocythemia (ET), juvenile chronic myeloid leukemia (JCML), and the so-called BCR/ABL- chronic myeloid leukemia (CML).