Gene mutations and clinical characteristics in children with juvenile myelomonocytic leukemia / 中国当代儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study gene mutations and clinical features in children with juvenile myelomonocytic leukemia (JMML).</p><p><b>METHODS</b>The clinical data of 14 children who were diagnosed with JMML and were examined for the detection of common gene mutations were retrospectively analyzed.</p><p><b>RESULTS</b>Eleven (79%) out of 14 cases were male, and 3 (21%) were female. The median age at diagnosis was 2.0 years (age range 0.6-6.0 years). Among 14 cases, there were 4 cases (29%) with PTPN11 mutation, 3 cases (21%) with N-RAS mutation, 1 case (7%) with PTPN11 mutation and K-RAS mutation, and 6 cases (43%) without any mutation. All four cases in the PTPN11 mutation group were male, and their median age was 2.5 years; interval from onset to diagnosis was 1.0 month; the white blood cell (WBC) count and absolute monocytes in peripheral blood were significantly higher, while the platelet (PLT) count was lower, as compared with the other three groups; they were followed up, and 3 cases died and 1 case had a progressive disease. In the N-RAS mutation group, there were two male cases and one female case, and their median age was 2.0 years; interval from onset to diagnosis was 13.7 months; after follow-up, 2 cases died and 1 case did not have an obviously progressive disease.</p><p><b>CONCLUSIONS</b>PTPN11 mutation is the most common mutation in JMML. The cases with PTPN11 mutation often have higher WBC count and absolute monocytes in peripheral blood, a lower PLT count, and a rapid disease progression, and their clinical outcomes are poor. The cases with N-RAS mutation have a slow disease progression. The clinical characteristics of the patients with compound mutations are not sure because of the small number of cases, and further clinical observation is indispensable.</p>