Juvenile myelomonocytic leukemia: a clinical and gene analysis of 21 cases

Abstract

Objective To analyze the clinical characteristics of juvenile myelomonocytic leukemia(JMML) and the PCNA levels of the hyperoxia- exposure group (6 h) decreased, and the difference in PCNA protein expression levels was significant of gene diagnose for JMML. Methods Clinical data were retrospectively analyzed in 21 patients suffering from JMML based on new 2009 World Health Organization diagnostic criteria from January 2013 to June 2014 in Beijing Children's Hospital, Capital Medical University. Results There were 85.7% (18/21 cases) patients within 4-year-old children, and the median age was 23 months (2-86 months). Fever and abdominal symptoms were the prominent clinical symptoms, 52.4% (11/21 cases) with fever, 38.1% (8/21 cases) with abdominal distention, diarrhea and other abdominal symptoms, 80.5% (19 /21 cases) had splenomegaly (mild 19.1%, middle 33.3%, severe 38.1%), and some patients had other tissue infiltration, such as rash, yellow tumor and lymphnode enlargement.Peripheral blood cell count showed that the white blood cells increased because of anemia or thrombocytopenia, ranging from 10.40×109/L to 82.14×109/L(median, 26.10×109/L), and the monocyte counts ranged from 1.46×109/L to 21.60×109/L(median, 3.79×109/L), characteristics of JMML gene abnormality was detected in 17 cases: including 11 single gene mutation, and 6 cases with double gene mutations.PTPN11 was the highest frequency of occurrence, accounting for 52.9% (9/17 cases), and NF1 mutation was 35.3% (6/17 cases). All the patients were followed up by phone call, the median follow-up time was 371 days (57-562 days), 6 patients were lost to follow-up, 7 patients died, 2 patients were alive after hematopoietic stem cell transplantation, 1 patient converted to acute non lymphocytic leukemia, and 5 patients were still alive after receiving symptomatic treatment.Among dead cases, PTNT11 gene mutation and NF1 gene mutation were detected in 6 patients; among living children after hematopoietic stem cell transplantation, RAS and PTNT11 mutations were detected in 2 patients; among living children after symptomatic treatment, RAS mutation was detected in 2 patients and PTPN11+ CBL mutation in 1 case. Conclusions The symptom and laboratory examination of JMML have no specificistics, with poor prognosis, gene diagnose has guiding significance for JMML diagnose and for selecting therapy. Key words: Juvenile myelomonocytic leukemia; Gene; Diagnosis; Treatment; Prognosis