伴有6号染色体长臂缺失的急性髓细胞白血病二例报告及文献复习

 目的　了解6q-异常急性髓细胞白血病（AML）的临床和生物学特点。方法　报道2例伴有6号染色体长臂缺失(6q-)的AML，并对伴有6q-异常AML的有关文献进行复习。结果　2例患者分别诊断为AML-M1和AML-M2，均表达髓系抗原，不表达淋巴细胞抗原。染色体核型分别为：46,XX, del(6)(q21q25),t(4;7)(q10;q10)3]/46,XX,del(6)(q21q25)2]/46,XX25]以及46,XX,del(6)(q23),t(7;11)(p15;p15)5]/46,XX,t(7;11)(p15;p15)9]/46,XX6]。现有文献共报道了伴有6q-异常AML 28例（包括该组报道的2例）。大部分患者伴有附加染色体异常。6q-的断裂点广泛分布于q12-q27，但主要累及6q21-q23区域。总体看来，伴有6q-异常的AML对化疗效果差、生存期短。6q-异常克隆本身可能导致了AML的临床恶性过程。AML患者出现6q-，可能与6号染色体长臂上myb以外癌基因的激活或抗癌基因的丢失有关。结论　AML伴有6q-异常很少见，具有自身的生物学特点，临床预后不良。

Deletions of chromosome 6q in two cases of acute myeloblastic leukemia and a review of the leterature

Objective To investigate the clinical and biologic characteristics of acute myeloid leukemia (AML) with 6q deletions (6q-). Methods Two cases of with 6q deletions (6q-) were here described, and all the AML cases with 6q- found in the literature were reviewed. Results Two cases were diagnosed with AMLMt and AML-M2, respectively. Myloloid markers were positive on the leukemia cells in both cases, none of them expressing lymphocytic antigens. The karyotype of these patients were 46,XX,del(6)(q21q25),t(4; 7)(q10;q10)3]/46,XX,del(6)(q21q25)2]/46,XX25], and 46,XX,del(6)(q23),t(7;11)(p15;p15)5]/46,XX,t(7;11)' (p15;p15)9]/46,XX 6]. Until now, 28 cases (including present 2 cases) of AML with 6q- have been documented in the world literature. Many of the AML patients with 6q -have additional chromosomal abnormalities. The breakpoints on 6q- were widely distributed from q12 to q27, mainly involved in the 6q21-23 region. Overall, the AML patients with 6q- were associated with an unfavorable clinical outcome, with a poor response to chemotherapy and a shorter duration. 6q-clone may itself confer a malignant clinical outcome. The 6q- found in some AML cases may associate with leukemogenesis via an activation of an oncogene other than myb or deletion of an antioncogene located in the long arm of chromosome 6. Conclusion Deletion of 6q is a very rare event in AML. AML with 6q- had distinct biologic features and a. poor clinical outcome.