Bone marrow (BM) failure (BMF) in children and young adults is often suspected to be inherited, but in many cases diagnosis remains uncertain. We studied a cohort of 179 patients (from 173 families) with BMF of suspected inherited origin but unresolved diagnosis after medical evaluation and Fanconi anemia exclusion. All patients had cytopenias, and 12.0% presented ≥5% BM blast cells. Median age at genetic evaluation was 11 years; 20.7% of patients were aged ≤2 years and 36.9% were ≥18 years. We analyzed genomic DNA from skin fibroblasts using whole-exome sequencing, and were able to assign a causal or likely causal germ line mutation in 86 patients (48.0%), involving a total of 28 genes. These included genes in familial hematopoietic disorders (GATA2, RUNX1), telomeropathies (TERC, TERT, RTEL1), ribosome disorders (SBDS, DNAJC21, RPL5), and DNA repair deficiency (LIG4). Many patients had an atypical presentation, and the mutated gene was often not clinically suspected. We also found mutations in genes seldom reported in inherited BMF (IBMF), such as SAMD9 and SAMD9L (N = 16 of the 86 patients, 18.6%), MECOM/EVI1 (N = 6, 7.0%), and ERCC6L2 (N = 7, 8.1%), each of which was associated with a distinct natural history; SAMD9 and SAMD9L patients often experienced transient aplasia and monosomy 7, whereas MECOM patients presented early-onset severe aplastic anemia, and ERCC6L2 patients, mild pancytopenia with myelodysplasia. This study broadens the molecular and clinical portrait of IBMF syndromes and sheds light on newly recognized disease entities. Using a high-throughput sequencing screen to implement precision medicine at diagnosis can improve patient management and family counseling. Key Points Next-generation sequencing broadens the spectrum of germ line mutations in a cohort of patients with likely-inherited BMF. Salient clinical features and distinct natural histories are consistently found in SAMD9L and SAMD9, MECOM/EVI1, and ERCC6L2 disorders. Visual Abstract

Key Points: Recurrent mutations in chromatin modifiers and cohesin were observed in t(8;21) AML, but not inv(16) AML. t(8;21) AML patients with mutations in kinase signaling plus chromatin modifiers or cohesin members had the highest risk of relapse.

Key Points: Mutations of key transcription factor in myeloid malignancies.

Purpose: Imatinib is the standard of care in adults with chronic myeloid leukemia (CML) in chronic phase (CP). Only a few studies to assess efficacy in children have been performed. We report on the results of the French prospective trial (ClinicalTrials.gov identifier NCT00845221) conducted in children and adolescents with newly diagnosed CML in CP. Patients and Methods: A total of 44 patients from age 10 months to 17 years with newly diagnosed CML in CP received daily imatinib 260 mg/m². Progression-free survival, responses, and tolerance were evaluated. Results: With a median follow-up times of 31 months (range, 11 to 64 months), the estimated progression-free survival rate at 36 months was 98% (95% CI, 85% to 100%). A complete hematologic response was achieved in 98% of the patients. The rates of complete cytogenetic response (CCyR) and major molecular response (MMR) were 61% and 31% at 12 months, respectively. During follow-up, CCyR and MMR were achieved in 36 children (77%) and 25 children (57%), respectively. Overall, 30% of the patients discontinued imatinib, mainly because of unsatisfactory response. The most common adverse events were neutropenia and musculoskeletal events. Conclusion: Imatinib is effective in children with CML in CP with response rates similar to rates reported in adults. The adverse effects are acceptable, but longer follow-up studies are required to fully assess the long-term impact.