Cytogenetic analysis of 358 bone marrow samples of suspected Acute Lymphoblastic Leukemia patients

ABSTRACT

Acute Lymphoblastic leukemia [ALL] is characterized by the accumulation of malignant, immature lymphoid cells in the bone marrow and in most cases also in peripheral blood. The disease is much more common in children than in older age group, with the incidence peaking around 3-5 years of age. Initial cytogenetic studies showed chromosomal aberrations in approximately half of all patients with ALL. Later studies and the combined use of FISH and molecular techniques have shown that the rates of detected chromosomal aberrations are 70% to 80% in these patients. The rates of detection in ALL have never been reported in Iran and we are reporting our cytogenetic findings in 358 ALL cases. We evaluated the karyotypes of 358 [21%] bone marrow samples sent to our center for cytogenetic study from patients with probable clinical diagnosis of ALL. All samples were submitted to a cell count and cultures were set up accordingly using standard protocols. Chromosomal aberrations were detected in 155 [49%] out of 314 successful cultures and the remaining 159 [51%] showed normal karyotypes. Hyperdiploidy in two forms of moderate and massive was the most common chromosomal aberration, found in 63 [40%] cases, followed by 14q abnormality in 13 [8%] and deletion of long arm of chromosome 6 in 9 [6%] of the cases. The ratios of detected numerical and structural chromosomal changes are close to and comparable with various series studies based on banding cytogenetic techniques alone. We believe that the implementation of complementary FISH and molecular cytogenetic techniques, and closer communication with the referring physicians are extremely instrumental in improving the effectiveness of cytogenetics study