Copy Number Variations and Gene Mutations Identified by Multiplex Ligation-Dependent Probe Amplification in Romanian Chronic Lymphocytic Leukemia Patients

Abstract

Chronic lymphocytic leukemia (CLL) is known for its wide-ranging clinical and genetic diversity. The study aimed to assess the associations between copy number variations (CNVs) and various biological and clinical features, as well as the survival rates of CLL patients and to evaluate the effectiveness of the multiplex ligation-dependent probe amplification (MLPA) technique in CLL patients.DNA was extracted from 110 patients, and MLPA was performed. Mutations in NOTCH1, SF3B1, and MYD88 were also analyzed. A total of 52 patients showed at least one CNV, 26 had at least one somatic mutation, and 10 presented both, CNVs, and somatic mutations. The most commonly identified CNVs were del(114.3), del(11q22.3), and dup(12q23.2). Other CNVs identified included del(17p13.1), del(14q32.33), dup(10q23.31), and del(19p13.2). One patient was identified with concomitant trisomy 12, 13, and 19. NOTCH1 and SF3B1 mutations were found in 13 patients each, either alone or in combination with other mutations or CNVs, while MYD88 mutation was identified in one patient. Forty-two patients had normal results. Associations between the investigated CNVs and gene mutations and patients’ overall survival were found. The presence of NOTCH1 and SF3B1 mutations or the combination of NOTCH1 mutation and CNVs significantly influenced the survival of patients with CLL. Both mutations are frequently associated with different CNVs. Del(13q) is associated with the longest survival rate, while the shortest survival is found in patients with del(17p). Even if MLPA has constraints, it may be used as the primary routine analysis in patients with CLL.