一例伴t（14；14）（q11;q32）易位的B细胞急性淋巴细胞白血病的临床和分子细胞遗传学研究

Clinical and molecular cytogenetic studies of a case of B-lineage acute lymphoblastic leukemia with t （14;14） （q11 ; q32）

目的报告1例伴t（14；14）（q11；q32）易位的罕见B细胞急性淋巴细胞白血病（B-lineage acute lymphoblastic leukemia，B-ALL）病例，阐明其临床和分子细胞遗传学特征。方法分析1例伴t（14；14）（q11；q32）易位B-ALL患者的临床资料；将患者骨髓细胞24h培养后按常规方法制备染色体标本，采用R显带技术进行核型分析；分别应用IGH双色断裂点分离探针、CEBPE双色断裂点分离探针、4号全染色体涂染探针和ALL组合探针进行荧光原位杂交（fluorescence in situ hybridization，FISH）分析。结果常规细胞遗传学分析显示患者核型为47，XX，＋4，t（14；14）（q11；q32）[20]，FISH分析进一步证实了这种核型异常。IGH双色断裂点分离探针FISH分析表明t（14；14）（q11；q32）易位累及IGH基因，CEBPE双色断裂点分离探针FISH分析提示t（14；14）（q11；q32）易位中IGH的伙伴基因为CEBPE基因。结论在昏ALL中t（14；14）（q11;q32）易位同时累及IGH和CEBPE基因为少见的再现性遗传学异常，该异常可定义辟ALL中一种新的亚型。伴有t（14；14）（q11；q32）IGH／CEBPE易位的昏ALL患者可能预后较好。

Objective To report on a rare case of B-lineage acute lymphoblastic leukemia （B-ALL） with t（14;14）（q11;q32） and clarify its clinical and molecular cytogenetic features. Methods Clinical data of a B-ALL patient with t （14; 14）（q11; q32） were analyzed. After 24 hour of unstimulated culturing, chromosome specimens of bone marrow cells were prepared with regular method, and R-banding was used for karyotype analysis. Fluorescence in situ hybridization （FISH） analysis was performed on fixed bone marrow cells using IGH dual-color break-apart probe, CEBPE dual-color break-apart probe, whole chromosome paint （WCP） probe for chromosome 4, and Chromoprobe Multiprobe-ALL System probe. Results The 39-year-old female was diagnosed with B-ALL based on morphologic and immunophenotypic analyses. Conventional cytogenetic analysis showed a karyotype of 47, XX, ＋ 4, t（ 14 ; 14） （q1 1 ; q32） [20], which was confirmed by FISH analysis. FISH using IGH dual-color break-apart probe confirmed involvement of IGH gene in t（14; 14）（q11;q32）, and FISH using CEBPE dual-color break-apart probe indicated that CEBPE is the partner gene involved in t （14;14）（q11;q32）. The patient achieved complete remission （CR） after a round of combined chemotherapy. At the time of follow-up, she had remained CR for more than 6 months. Conclusion t（14;14）（q11;q32） simultaneously involving IGH and CEBPE genes in B-ALL is a rare hut recurrent genetic abnormality that may identify a new subgroup of B-ALL. In B-ALL patients, t（14;14）（q11 ;q32） involving IGH/CEBPE translocation may indicate a better prognosis.