Characterization of Three Somatic Mutations in the 3'UTR of and Their Inverse Correlation with Lymphocytosis in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a hematologic malignancy characterized by progressive accumulation of a rare population of CD5+ B-lymphocytes in peripheral blood, bone marrow, and lymphoid tissues. CLL exhibits remarkable clinical heterogeneity, with some patients presenting with indolent disease and others progressing rapidly to aggressive CLL. The significant heterogeneity of CLL underscores the importance of identifying novel prognostic markers. Recently, the RAS-related gene has emerged as both a driver oncogene and a potential marker for CLL progression, with higher expression associated with poorer disease prognosis. Although missense somatic mutations in the coding sequence of have not been described in CLL, this study reports the frequent detection of three somatic mutations in the 3' untranslated region (3'UTR) affecting positions +26, +53, and +180 downstream of the stop codon in the mRNA. An inverse relationship was observed between these three somatic mutations and mRNA expression, which correlated with lower blood lymphocytosis. These findings highlight the importance of overexpression in CLL development and prognosis and point to somatic mutations in its 3'UTR as novel mechanistic clues. Our results may contribute to the development of targeted therapeutic strategies and improved risk stratification for CLL patients.