OBJECTIVETo study the clinical and laboratory characteristics of juvenile myelomonocytic leukemia (JMML).

METHODSThe clinical characteristics and laboratory results were retrospectively analyzed in 10 children with newly diagnosed JMML. They were compared with those of 28 children with myelodysplastic syndrome (MDS) and 44 children with chronic myeloid leukemia (CML).

RESULTSCompared with the children with CML or MDS, the children with JMML had significantly higher rates of skin rashes, ecchymosis, and lymphadenectasis, a significantly lower serum cholinesterase (ChE) level, and a significantly higher fetal hemoglobin level (P<0.05). The white blood cell count of children with JMML was significantly higher than that of children with MDS, but significantly lower than that of children with CML (P<0.05). In addition, the myeloid/erythroid ratio and rate of dyshaematopoiesis were significantly lower in children with JMML than those in children with CML or MDS. The children with JMML had a significantly higher expression of mature monocyte marker CD14 than those with CML or MDS (P<0.05). The levels of myeloid markers CD33, CD11b, CD13, and CD15 in children with JMML were significantly higher than those in children with MDS, but significantly lower than those in children with CML (P<0.05). The levels of CD2 and CD7 in children with JMML were higher than those in children with CML, but lower than those in children with MDS (P<0.05).

CONCLUSIONSSkin rashes, ecchymosis, lymphadenectasis, and ChE reduction are more common in children with JMML than in those with CML or MDS, while dyshaematopoiesis is less common. In addition, CD14 level increases significantly in children with JMML.

Child ; Child, Preschool ; Female ; Humans ; Infant ; Leukemia, Myelomonocytic, Juvenile ; genetics ; immunology ; Lipopolysaccharide Receptors ; analysis ; Male

OBJECTIVE: To study the clinical and genetic features of juvenile myelomonocytic leukemia (JMML) and the association between genotype and prognosis. Methods The clinical data of 15 children who were diagnosed with JMML were collected. Next-generation sequencing was used to detect common gene mutations of JMML. RESULTS: The male/female ratio was 6.5:1, and the age of onset was 19 months (range 2-67 months). Of the 15 children, 11 (73%) experienced disease onset before the age of 4 years, with abdominal distension and pyrexia as initial symptoms. All children had hepatosplenomegaly and superficial lymphadenectasis, with a number of peripheral blood mononuclear cells of >1.0×10/L and a percentage of juvenile cells of 1%-7% in peripheral blood smear. The percentage of bone marrow blasts + juvenile cells was <20%, and the percentage of monoblasts + promonocytes was 1%-10%. Of the 15 children, 10 (67%) had a higher level of hemoglobin F than the normal level at the corresponding age, with the highest level of 62.5%. All 15 children had the absence of Philadelphia chromosome, and one child had chromosome 7 deletion. All 15 children had a negative result of BCR/ABL fusion gene detection. PTPN11 gene mutation was found in 5 children (33%), NF1 mutation in 4 children (27%), CBL mutation in 3 children (20%), and RAS mutation in 3 children (20%). No children received regular chemotherapy, and one child underwent hematopoietic stem cell transplantation. The median follow-up time of 15 children was 18 months (range 1-48 months). Among the 15 children, 8 died (among whom 4 had PTPN11 gene mutation, 3 had NF1 mutation, and 1 had RAS mutation) and 7 survived. The children with PTPN11 mutation had the worst prognosis and the highest mortality rate, and those with CBL or NRAS mutation had a relatively good prognosis. The level of hemoglobin F was negatively correlated with survival time (r=-7.21, P=0.002). CONCLUSIONS In children with JMML, the type of gene mutation is associated with prognosis. The children with PTPN11 mutation often have a poor prognosis, and those with CBL or NRAS mutation have a relatively good prognosis.
Adolescent ; Child ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Leukemia, Myelomonocytic, Juvenile ; genetics ; Leukocytes, Mononuclear ; Male ; Mutation ; Prognosis

OBJECTIVETo study gene mutations and clinical features in children with juvenile myelomonocytic leukemia (JMML).

METHODSThe clinical data of 14 children who were diagnosed with JMML and were examined for the detection of common gene mutations were retrospectively analyzed.

RESULTSEleven (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.

CONCLUSIONSPTPN11 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.

Child ; Child, Preschool ; Female ; Genes, ras ; Humans ; Infant ; Leukemia, Myelomonocytic, Juvenile ; blood ; genetics ; Male ; Mutation ; Protein Tyrosine Phosphatase, Non-Receptor Type 11 ; genetics ; Retrospective Studies

OBJECTIVE: To analyze the gene mutations of children with juvenile myelomonocytic leukemia (JMML) and their correlation with clinical characteristics. METHODS: The genetic mutation results and clinical data of 19 children with JMML in Fujian from January 2015 to December 2018 were collected and analyzed retrospectively. According to the results of gene mutation, they were divided into PTPN11 gene mutation group and non-PTPN11 gene mutation group, and the clinical characteristics and prognosis of children with JMML between two groups were compared. RESULTS: Among the 19 children with JMML, 14 cases were male and 5 cases were female, and male/female ratio was 2.8∶1. The median age at diagnosis was 13(3-48) months, and 14 cases (73.68%) were less than 2 years old. Abdominal distension and pyrexia were the common initial symptoms, and all the children with JMML had splenomegaly. The median white blood cell count was 39.82(4.53-103.4)×10 CONCLUSION JMML is more common in male infancy and toddlerhood, and the main gene mutation types are PTPN11 and Ras mutations. Because the JMML children with PTPN11 mutations show particularly rapid disease progression, if there is no timely intervention, most children die in a short period of time. Therefore, early HSCT may improve the prognosis of the children with JMML.
Child ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Infant ; Leukemia, Myelomonocytic, Juvenile/genetics* ; Male ; Mutation ; Prognosis ; Protein Tyrosine Phosphatase, Non-Receptor Type 11/genetics* ; Retrospective Studies