IX. Chronic lymphocytic leukaemia: New genetic markers as prognostic factors

In Western countries, chronic lymphocytic leukaemia (CLL) is the most frequent mature B-cell malignancy [1]. The course of CLL ranges from very indolent, with a nearly normal life expectancy, to rapidly progressive leading to early death. Understand the genetic basis of CLL may help in clarifying the molecular determinants of this clinical heterogeneity and improve patients’ prognostication. Recurrent chromosomal aberrations at 13q14, 12q, 11q22q23 and 17p13 are the first genetic lesions identified as drivers of the disease and have enabled the construction of a hierarchical model of cytogenetic abnormalities that correlates with outcome. Cytogenetic lesions, however, may not entirely explain the genetic basis of CLL clinical heterogeneity, as documented by the contribution of TP53 mutation assessment in identifying high-risk patients [1]. The recent major improvements in massive parallel sequencing technologies have provided an opportunity to examine the CLL genome, allowing for the identification of genomic alterations underlying the disease and for the discovery of new therapeutic targets and clinically predictive biomarkers such as NOTCH1, SF3B1 and BIRC3 mutations [2–5].