Cytogenetic Profile of De Novo B lineage Acute Lymphoblastic Leukemia: Determination of Frequency, Distribution Pattern and Identification of Rare and Novel Chromosomal Aberrations in Indian Patients

Background: Chromosomal aberrations identified in acute lymphoblastic leukemia (ALL) have an importantrole in disease diagnosis, prognosis and management. Information on karyotype and associated clinical parametersare essential to physicians for planning cancer control interventions in different geographical regions. Materialsand
Methods: In this study, we present the overall frequency and distribution patterns of chromosomal aberrationsin both children and adult de novo B lineage ALL Indian patients using conventional cytogenetics, interphaseFISH and multiplex RT-PCR.
Results: Among the 215 subjects, cytogenetic results were achieved in 172 (80%)patients; normal karyotype represented 37.2% and abnormal 62.8% with a distribution as follows: 15.3%hypodiploidy; 10.3% hyperdiploidy; 15.8% t(9;22); 9.8% t(1;19); 3.7% t(12;21); 2.8% t(4;11); 2.8% complexkaryotypes. Apart from these, we observed several novel, rare and common chromosomal rearrangements. Also,FISH studies using LSI extra-signal dual-color probes revealed additional structural or numerical changes.
Conclusions: These results demonstrate cytogenetic heterogeneity of ALL and confirm that the incidence ofchromosomal abnormalities varies considerably. To the best of our knowledge, this is one of the largest reportedseries of cytogenetic investigations in Indian B-lineage ALL cases. In addition, ongoing cytogenetic studies arewarranted in larger groups of B-lineage ALL cases to identify newly acquired chromosomal abnormalities thatmay contribute to disease diagnosis and management.