Cytogenetic abnormalities in acute lymphoblastic leukemia

Acute lymphoblastic leukemias (ALL) represent malignant clonal proliferations of stem cells commited in lymphoid differentiation, B or T-cell ALL. Clonal chromosomal abnormalities are found in 80% children and 70% adult cases. They are associated with an independant prognostic value which modifies the therapeutic approach and therefore karyotyping at diagnosis is mandatory. Molecular techniques such as FISH and RT-PCR are very helpful too as cryptic chromosomal abnormalities have been described. In this review, numerical and structural abnormalities are described : frequency, diagnosis and prognosis value as well as genes involved in structural abnormalities. [Copyright &y& Elsevier]