Key Points• A comprehensive study of 19 gene mutations and their cooperation, including the first report of ASXL1 and TET2 mutations in pediatric AML.• The development of pediatric AML requires fewer gene mutations than adult AML.Gene mutations involving epigenetic regulators recently have been described in adult acute myeloid leukemia (AML). Similar studies are limited in children. We analyzed gene mutations and cooperation in pediatric AML with special reference on mutated epigenetic regulators. Nineteen gene mutations, including 8 class I genes, 4 class II genes, WT1 and TP53 (class III), and 5 epigenetic regulator genes (class IV), were analyzed in 206 children with de novo AML. Mutational analysis was performed with polymerase chain reaction2 based assay followed by direct sequencing. One hundred seventeen of 206 patients (56.8%) had at least one mutation: 51% class I, 13% class II, 6.8% class III, and 5.6% class IV. FLT3-internal tandem duplication was most frequent, and 29% of patients had more than one gene mutation. Two patients carried ASXL1 mutations, both with t(8;21), 2 had DNMT3A mutations, 2 had IDH1 mutations, 1 had IDH2 mutation, and 3 had TET2 mutations. Both patients with IDH1 mutations had AML-M0 subtype and MLL-partial tandem duplication. Cooperating mutations with mutated epigenetic regulators were observed in 8 of 10 patients. We conclude that mutated epigenetic regulators were much less than those in adult AML but with frequent cooperating mutations. ASXL1, TET2, and IDH1 mutations were associated with specific genetic subtypes. (Blood. 2013;121(15):2988-2995 IntroductionComprehensive analyses in de novo childhood acute myeloid leukemia (AML) of gene mutations involving epigenetic regulators have been limited. The ASXL1 (additional sex comb-like 1) gene mapping to chromosome 20q acts as a cofactor of retinoic acid receptor via binding to steroid receptor coactivation-1 and belongs to enhancer of trithorax and polycomb genes that can both activate and repress the HOX gene.1,2 Very recently, it has been demonstrated that ASXL1 loss-of-function mutations result in the loss of polycomb repressive complex 22mediated histone H3 lysine 27 trimethylation, which promotes myeloid leukemia transformation.3 ASXL1 mutations conferred a poor outcome in adult AML, 4,5 but there have been no reports of ASXL1 mutations in childhood AML. TET proteins encode a-ketoglutarate-dependent oxygenases, which are involved in the conversion of 5-methylcytosine to 5-hydroxymethylcytosine. 6 TET2 protein is important for normal myelopoiesis, and disruption of TET2 enzymatic activity results in altered DNA methylation and favors myeloid neoplasm transformation.7 IDH1 and IDH2 mutations convert a-ketoglutarate to 2-hydroxyglutarate, which disrupts TET2 function. 8,9 Somatic mutations of TET2 were identified with microdeletion at 4q24 in myeloid neoplasms by the use of high-resolution single-nucleotide polymorphism microarrays.10,11 TET2 mutations were detected in adult AML with a frequency ranging from 7% to 23%, but t...

Objective Juvenile localized scleroderma (LS) is a chronic inflammatory skin disorder associated with substantial morbidity and disability. Although a wide range of therapeutic strategies has been reported in the literature, a lack of agreement on treatment specifics and accepted methods for clinical assessment has made it difficult to compare approaches and identify optimal therapy. Our objective was to develop standardized treatment plans, clinical assessments, and response criteria for active, moderate to high severity juvenile LS. Methods A core group of pediatric rheumatologists, dermatologists, and a lay advisor was engaged by the Childhood Arthritis and Rheumatology Research Alliance (CARRA) to develop standardized treatment plans and assessment parameters for juvenile LS using consensus methods/nominal group techniques. Recommendations were validated in 2 face‐to‐face conferences with a larger group of practitioners with expertise in juvenile LS and with the full membership of CARRA, which encompasses the majority of pediatric rheumatologists in the US and Canada. Results Consensus was achieved on standardized treatment plans that reflect the prevailing treatment practices of CARRA members. Standardized clinical assessment methods and provisional treatment response criteria were also developed. Greater than 90% of pediatric rheumatologists responding to a survey (66% of CARRA membership) affirmed the final recommendations and agreed to utilize these consensus plans to treat patients with juvenile LS. Conclusion Using consensus methodology, we have developed standardized treatment plans and assessment methods for juvenile LS. The high level of support among pediatric rheumatologists will support future comparative effectiveness studies and enable the development of evidence‐based guidelines for the treatment of juvenile LS.

The long-term outcome of 1390 children with acute lymphoblastic leukemia (ALL), treated in two successive clinical trials (Taiwan Pediatric Oncology Group (TPOG)-ALL-97 and TPOG-ALL-2002) between 1997 and 2007, is reported. The event-free survival improved significantly (P ¼ 0.0004) over this period, 69.3±1.9% in 1997-2001 to 77.4±1.7% in 2002-2007. A randomized trial in TPOG-97 testing L-asparaginase versus epidoxorubicin in combination with vincristine and prednisolone for remission induction in standard-risk (SR; low-risk) patients yielded similar outcomes. Another randomized trial, in TPOG-2002, showed that for SR patients, two reinduction courses did not improve long-term outcome over one course. Decreasing use of prophylactic cranial irradiation in the period 1997-2008 was not associated with increased rates of CNS relapse, prompting complete omission of prophylactic cranial irradiation from TPOG protocols, beginning in 2009. Decreased use of etoposide and cranial irradiation likely contributed to the low incidence of second cancers. High-risk B-lineage ALL, T-cell, CD10 negativity, t(9;22), infant, and higher leukocyte count were consistently adverse factors, whereas hyperdiploidy 450 was a consistently favorable factor. Higher leukocyte count and t(9;22) retained prognostic significance in both TPOG-97 and TPOG-2002 by multivariate analysis. Although long-term outcome in TPOG clinical trials is comparable with results being reported worldwide, the persistent strength of certain prognostic variables and the lower frequencies of favorable outcome predictors, such as ETV6-RUNX1 and hyperdiploidy 450, in Taiwanese children warrant renewed effort to cure a higher proportion of patients while preserving their quality of life.

BACKGROUND Recently, an internal tandem duplication of the FLT3 gene (FLT3/ITD) was found in approximately 20% of adult acute myeloid leukemia (AML) cases and associated with a poor outcome. However, there are few studies on FLT3/ITD in childhood AML, and the clinical significance of FLT3/ITD is thus unclear. METHODS FLT3/ITD was analyzed in 80 children with de novo AML. The genomic DNA polymerase chain reaction (PCR) assay was performed to identify FLT3/ITD. Genescan analysis to determine the allelic distribution was then performed for those PCR products with aberrant bands. Direct sequencing of PCR products was also carried out in each sample with FLT3/ITD. RESULTS The incidence of FLT3/ITD was 11.3% (9 out of 80 patients) in AML, with 25% (3 out of 12 patients) in acute promyelocytic leukemia (APL) and 8.8% (6 out of 68 patients) in non‐M3 AML. The size of duplicated fragments varied from 21 base pairs (bp) to 75 bp, and the mutant to wild type ratio of FLT3 ranged from 0.28 to 16.60 in the nine patients with FLT3/ITD. The incidence of FLT3/ITD in childhood AML in patients > 10 years of age was 24%, compared to 5% of those patients ≤ 10 years of age (P = 0.011). The six non‐M3 AML patients with FLT3/ITD were all older than 10 years of age. In APL, FLT3/ITD was found in 2 of 2 patients with S‐form PML/RARα, compared with 1 in 10 patients with non‐S form PML/RARα(P = 0.045). There were no cytogenetic abnormalities or fusion transcripts derived from common specific translocations found in non‐M3 AML patients with FLT3/ITD. There was no significant difference in treatment outcome between APL patients with FLT3/ITD and those without FLT3/ITD. The authors failed to find a correlation between the treatment outcome and the presence of FLT3/ITD in non‐M3 AML patients. Instead, the authors found that all three patients with a mutant FLT3 to wild type ratio of greater than 2.0 died within eight months after diagnosis; two of them failed to achieve complete remission. CONCLUSIONS The current study shows that the mutant FLT3 to wild type ratio, but not the presence of FLT3/ITD itself, may serve as a potential marker to improve risk‐assessment in childhood AML. Cancer 2002;94:3292–8. © 2002 American Cancer Society. DOI 10.1002/cncr.10598