Occurrence of high hyperdiploid karyotypes in childhood Acute Lymphoblastic Leukemia

Abstract Introduction/Objective High hyperdiploidy is defined as the non-random gain of chromosomes, increasing the modal chromosome number from 46 to between 51 and 65 or 67. This condition is the most common finding in childhood acute lymphoblastic leukemia, with a good outcome. It is generally characterized by the gain of chromosomes, typically X, 4, 6, 10, 14, 17, 18, and 21. The objective of this study is to determine the frequency of high hyperdiploidy in childhood ALL. Methods/Case Report Cytogenetic results of 435 patients, reported between October 2020 and September 2022 were reviewed retrospectively. All individuals were suspected for ALL between ages 1-15 years. Chromosomal analysis was performed in the Cytogenetics Lab of the Indus hospital and health network. Fluorescent in-situ hybridization (FISH) analysis were also carried out with probes for co-relating the gain of chromosomes. Results (if a Case Study enter NA) A total of 435 individuals were successfully karyotyped, 82 karyotypes showed hyperploidy without any additional abnormality, 213 patients showed hyperploidy along with additional structural aberrations, and 143 individuals showed normal karyotype. Among all the hyperploid karyotypes, chromosomes X, 4, 6, 10, 14, 17, 18, 21 were all gained in approximately 70% of the cases. Whereas, chromosome 21 was gained in 100% of all cases. FISH results also showed the gain of signals for particular probes including chromosomes 8, 9, 11, 12, 21 and 22. Conclusion In summary, this study leads to the fact that high hyperdiploidy is the most common abnormality in childhood acute lymphoblastic leukemia. It is assured that the occurrence of constituent trisomies of certain chromosomes is linked with the prognosis of the disease and also helps in determining the differences in treatment of the disease. Furthermore, correlation of karyotypes with the FISH results have also played a vital role in increasing the accuracy of results in this study.