3q26 chromosomal anomalies in acute myeloid leukemia: First descriptions from India.

Cytogenetic anomalies involving the 3q26 chromosomal region are rare in acute myeloid leukemia (AML). There is no such description of these anomalies from the Indian sub-continent. A total of 174 AML patients were admitted to our hospital for therapy between January 2001 and January 2008. Cytogenetic studies could be done in 115 patients; which revealed three cases with 3q26 anomalies. All were males. In the first two cases, the anomaly was detected in all the metaphases. The common features seen were the presence of only mild thrombocytopenia (relatively high platelet counts when assessed against the background of AML with high blast percentages), monosomy 7, myeloperoxidase positive blasts, mild eosinophilia, and poor therapeutic response. In the third case, the chromosome 3 anomaly was present in only one metaphase. Such an anomaly has not been reported. Only the third patient responded to induction therapy but subsequently relapsed after being in complete remission for 15 months. 3q26 anomalies are associated with monosomy 7, relatively higher platelet counts at diagnosis as compared with other non-3q rearranged AML's and poor prognosis. The precise mechanisms underlying leukemogenesis need to be elucidated and better treatments devised since these patients respond poorly to therapy.