Shashok for improving the use of English in the manuscript. This research was financially supported by the Kinase Inhibitor Library Health Policy Research Center at Shiraz University of Medical Sciences (grant No#HP29-90). Conflict of interest: None declared.
Background: Acute lymphoblastic leukemia (ALL) is the sixth most common malignancy in Iran. Cytogenetic analysis of leukemic blasts plays an important role in classification and prognosis in ALL patients. The purpose of this study was to define the frequency of chromosomal abnormalities of ALL patients in adults and children in Fars province, Iran. Methods: In this cross-sectional study, we

evaluated karyotype results of bone marrow specimens in 168 Iranian patients with ALL (154 B-ALL and 14 T-ALL) in Fars Province Inhibitors,research,lifescience,medical using the conventional cytogenetic G-banding method. Results: The frequency of cytogenetic abnormalities, including numerical and/or structural changes, was 61.7% and 53.8% in the B-ALL and T-ALL patients,

respectively. Hyperdiploidy was the most common (32%) cytogenetic abnormality. Among structural abnormalities, the most Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical common was t(9;22) in 11% of the patients. The children showed a higher incidence of hyperdiploidy and lower incidence of t(9;22) than adults (P<0.05). We found a lower incidence of recurrent abnormalities such as 11q23, t(1;19), and t(12;21) than those reported in previous studies. Conclusion: Normal karyotype was more frequent in our study. The frequencies of some cytogenetic abnormalities such as hyperdiploidy and t(9;22) in our study were comparable to those reported in the literature. The results of this study in Fars Province can be used as baseline information for treatment decision and research purposes in ALL patients. We recommend the use of advanced molecular techniques in the future to better Inhibitors,research,lifescience,medical elucidate cryptic

cytogenetic abnormalities. Inhibitors,research,lifescience,medical Key Words: Acute lymphoblastic leukemia, Cytogenetic analysis, Chromosomal abnormalities, Incidence, Iran Introduction Acute leukemia is a clonal expansion of white blood cell precursors in the blood, bone marrow, and various extramedullary tissues. The diagnosis of acute leukemia is based on the presence of more than 20% blasts in the peripheral blood or bone marrow. According to a recent study, hematologic malignancies are the sixth most commonly occurring malignancies in Iran in both sexes. Annual occurrence of leukemia disorders in the northwest of Iran was 3.7 (4.2–5.6) per 100,000 population.1 The French-American-British Phosphoprotein phosphatase Cooperative classification of acute leukemia published in 1976, was based on morphology by the Romanowsky staining of bone marrow or peripheral blood films, and the World Health Organization (WHO) supervised classification according to molecular and cytogenetic studies.2 There are three varieties of recurrent genetic aberration in acute leukemia: (1) numerical abnormalities, including gain or loss of whole or segments of chromosomes; (2) balanced chromosomal translocations; and (3) molecular genetic abnormalities.