Association of Specific Gene Mutations with Immunoglobulin Heavy-Chain Variable Region and Chromosomal Alterations in Chronic Lymphocytic Leukemia Patients in India.

Chronic lymphocytic leukemia (CLL) is a less common hematological malignancy in Indian people. It accounts for less than 5% of all leukemias. Information on genomic alteration in CLL is limited immunoglobulin heavy-chain variable region (IGHV) mutational status is considered the most reliable prognostic marker. In this study, we performed mutation analysis of significantly mutated genes of CLL and correlated them with the IGHV mutational status and cytogenetic alterations. We included 97 patients in this study; 36 were IGHV hypermutated, and 61 were IGHV unmutated. We observed frequent mutations in TP53 (16.4%), ATM (19.5%), SF3B1 (18.5%), and NOTCH1 (14.2%). NOTCH1 mutations were significantly observed in patients with unmutated IGHV. We observed that patients with no mutations in ATM, NOTCH1, or TP53 had chromosomal alterations (del 11q, del 13q, del 17q, and trisomy 21) identified by FISH. Our results have shown mutations in essential genes and their association with IGHV status. Overall, specific gene mutations, IGHV status, and chromosomal alterations can provide information on prognosis.