二例伴有dic(9;20)(p11-13;q11)急性淋巴细胞白血病患者的临床和实验研究

目的探讨伴有dic（9;20）（p11-13;q11）的急性淋巴细胞白血病（ALL）的细胞形态学、免疫学、细胞遗传学特征和临床特点.方法骨髓细胞经直接法和24h短期培养后按常规方法制备染色体,采用R显带技术进行细胞遗传学分析.分别以9号和20号染色体着丝粒探针进行双色荧光原位杂交（FISH）检测.结果2例患者的临床和血液学改变符合ALL诊断,免疫表型分析B淋系标志阳性（CD10＋、HLA-DR＋）;染色体核型分析显示2例患者均为dic（9;20）：例1为45,XY,der（9）t（9;20）（p11;q11）,-20[20],例2为45,XX,der（9）t（9;20）（p13;q11）,t（9;22）（q34;q11）,-20[10]/46,idem,＋8[16]/47,idem,＋8,＋21[14];其中1例经双色FISH检测证实9号和20号染色体之间发生了相互易位,且形成双着丝粒染色体.结论dic（9;20）（p11-13;q11）是一种少见的重现性核型异常,可能和ALL有特殊的联系.FISH技术是检测该易位的可靠手段.

Clinical and laboratory characteristics of two acute lymphoblastic leukemia patients with dicentric (9;20) (p11-13; q11 )

OBJECTIVE: To explore the morphologic, immunophenotypic, cytogenetic and clinical features of acute lymphoblastic leukemia (ALL) patients with dicentric (9; 20) (p11 - 13; q11). METHODS: Chromosome specimens of bone marrow cells were prepared by direct method and/or short-time culture. Karyo-typing was performed by R-banding technique. Dual-color fluorescence in situ hybridization (FISH) was performed using both chromosome 9 classical satellite probe and chromosome 20 alpha-satellite probe in one patient. RESULTS: The two ALL patients were positive for CD10 and HLA-DR, showing of B cell origin. Both patients had dicentric (9; 20): case 1 was 45, XY, der (9) t (9; 20) (p11; q11), -20[20]; case 2 was 45, XX, der (9) t (9; 20) (p13; q11), t (9; 22) (q34; q11), -20[10]/46, idem, +8[16]/47, idem, +8, +21[14]. Mutual translocation between chromosomes 9 and 20 of the dicentric chromosome was confirmed by FISH in one patient. CONCLUSIONS: Dicentric (9; 20) (p11 - 13; q11) is a rare recurring chromosome abnormality associated with ALL. Because of the subtle nature of the translocation, FISH is essential for the detection of this abnormality.