Rare Cytogenetic Abnormalities Showing both MLL Rearrangement and Philadelphia Chromosome Positive in Pediatric Acute Lymphoblastic Leukemia Patients.

ABSTRACT

Objective: To evaluate the cytogenetics abnormalities in pediatric ALL cases and to correlate the cytogenetics Philadelphia chromosome - positive with the Fluorescence In - Situ Hybridization results. Methods: Retrospective cytogenetics and FISH analysis of the Bone marrow samples of both adult and pediatric patientswere done. However, since the inclusion criteria for this study was pediatric ALL, only the data of the pediatric patients were taken for this study. For the prospective samples, the cytogenetic analyses and Fluorescence in - Situ Hybridization were performed on the procured samples. The cytogenetics and FISH test were performed as per the standard protocol of our lab and were analysed as per the standard guideline. The cytogenetics Philadelphia chromosome - positive were correlated with the Fluorescence In - Situ Hybridization results and vice versa. Results: In our study of 50 pediatric ALLB patients, two patients showed low Ph+ by FISH. A confirmatory test by conventional cytogenetics revealed a rare association of Philadelphia chromosome positive along with the cytogenetics abnormality involving the MLL gene as well. One of the patient showed a karyotype of 46,XY,del(9) (p21),t((10;11)(p12;q21)[7]/46,XY,del(9)(p21)[9]/46,XYdel(22)(q11.2)[3] and the other patient showed 46, XX, t(9;11) (p13;q23)),?del(22)(q11.2)[6]/46,XX,del (11) (q23) [8]/46, XX[5] which were confirmed by cytogenetics and Fluorescence In - Situ Hybridization (FISH). Two patients showed complete Ph+ve and one patient showed normal karyotype along with tetraploidy. The rest of the cases showed either a normal karyotype or an insignificant abnormality. Conclusion: In our study of 50 pediatric ALL patients, two cases showed a rare association of Philadelphia chromosome positive along with a cytogenetics abnormality involving the MLL gene. Apart from the rare findings in our study, emphases is also made on the confirmatory test by cytogenetics incidence of low Ph+ve by FISH and vice versa and a need for larger collaborative studies and intense follow up of the treatment and the prognosis of this subset of patients to determine the prognostic pattern to improve the treatment options for these kind of rare patients.