Genetic Lesions in Russian CLL Patients with the Most Common Stereotyped Antigen Receptors

Chronic lymphocytic leukemia (CLL) is one of the most common B-cell malignancies in Western countries. IGHV mutational status is the most important prognostic factor for this disease. CLL is characterized by an extreme narrowing of the IGHV genes repertoire and the existence of subgroups of quasi-identical stereotyped antigenic receptors (SAR). Some of these subgroups have already been identified as independent prognostic factors for CLL. Here, we report the frequencies of TP53, NOTCH1, and SF3B1 gene mutations and chromosomal aberrations assessed by NGS and FISH in 152 CLL patients with the most common SAR in Russia. We noted these lesions to be much more common in patients with certain SAR than average in CLL. The profile of these aberrations differs between the subgroups of SAR, despite the similarity of their structure. For most of these subgroups mutations prevailed in a single gene, except for CLL#5 with all three genes affected by mutations. It should be noted that our data concerning the mutation frequency in some SAR groups differ from that obtained previously, which could be due to the population differences between patient cohorts. The research in this area should be important for better understanding the pathogenesis of CLL and therapy optimization.