Genomic assessment of pediatric acute leukemia

Advances in molecular genetics have revolutionized our understanding of acute myeloid and lymphoblastic leukemia. Structural and numerical chromosomal aberrations are common, and their detection is vital for leukemia diagnosis, risk stratification, and monitoring of response to therapy. Fusion proteins resulting from chromosomal translocations are necessary but not sufficient for leukemogenesis, and there is intense research activity to elucidate the cooperating molecular abnormalities that may be suitable targets for novel therapeutic approaches. Candidate gene approaches have identified mutations in kinases and transcription factors in a proportion of patients, but more comprehensive genomic approaches are required. Gene expression profiling accurately classifies known subtypes of acute leukemia and has highlighted potentially leukemogenic abnormalities in gene expression. Newer techniques, such as single-nucleotide polymorphism arrays to analyze changes in gene copy number and zygosity, cancer genome sequencing, and RNA interference, are promising tools to identify mutations, although at present, data from these approaches are limited. This review provides an overview of these techniques in clinical practice and as research tools to develop new therapeutic approaches in pediatric leukemia.