Utilità clinica dell'array-CGH nello studio di pazienti in età pediatrica con Leucemia Linfatica Acuta

Acute leukemia represent the most common malignancy in children, with the 80% of cases of lymphoblastic type. Most patients with acute lymphocytic leukemia are reported to have acquired chromosomal abnormalities in their leukemic bone marrow cells. Multiple chromosome rearrangements have been described, and their associations with specific clinical, biologic, and prognostic features are well defined. Conventional cytogenetic analysis is critical in the diagnosis of LLA, identifying characteristic chromosomal abnormalities associated with a given prognosis, therein facilitating optimized treatment. We investigated the utility of array comparative genomic hybridization (array-CGH) for detection of chromosomal abnormalities compared to standard clinical evaluation with karyotype and fluorescent in-situ hybridization (FISH). In the present study 19 LLA pediatric bone marrows were analyzed, 12 diagnosis and 7 relapse sample. Array-CGH detected unbalanced chromosome rearrangements in all cases except testicular relapses. The most recurrently altered chromosome regions were 9p ( deletion of CDKN2A/B, JAK2, PAX5 genes) and 21q (amplification of RUNX1 gene). The complementary use of microarray and conventional cytogenetics would allow for more sensitive, comprehensive, and accurate analysis of the underlying genetic profile, with concomitant improvement in prognosis and treatment for pediatric LLA.