慢性髓细胞白血病的细胞遗传学和荧光原位杂交分析

The analysis of cytogenetics and fluorescence in situ hybridization of 196 cases of chronic myeloid leukemia

目的 探讨慢性髓细胞白血病（chronic myeloid leukemia,CML）细胞遗传学、分子遗传学特点及其临床意义.方法 选择196例CML患者,采用直接法和（或）24 h短期培养法制备骨髓染色体标本,采用R显带技术（RHG）进行染色体核型分析;用BCR-ABL双色双融合探针或ES探针对骨髓间期细胞进行荧光原位杂交（fluorescence in situ hybridization,FISH）检测.结果 将患者分为慢性期和加速/急变期2组.细胞遗传学分析：附加染色体异常、变异易位在2组中比例分别为9/166（5.4%）、7/166（4.2%）和19/30（63.3%）、3/30（10.0%）.196例患者中检出179例Ph阳性标本,占91.3%;其中典型易位169例（94.4%）,变异易位10例（5.6%）,附加染色体异常出现频率最多的为双Ph、＋ 8、I（17q）、-Y.分子遗传学分析：68例患者行FISH 检测,均为BCR-ABL融合基因阳性（含10例变异易位、11例Ph染色体阴性及6例染色体检测失败者）,其中10例（14.7%）为der（9）缺失（含1例染色体检测失败者）,在慢性期、加速/急变期中比例分别为8/55（14.5%）、2/13（15.4%）.68例患者中典型易位41例,变异易位10例,der（9）缺失在典型易位、变异易位中比例分别为5/41（12.2%）和4/10（40.0%）.结论 与慢性期相比,加速/急变期附加染色体、变异易位等异常明显增加,染色体核型分析有助于疾病诊断和进展的分析,并且在遗传学分析的基础上,选用分子遗传学FISH技术可以明显提高疾病的诊断率和染色体异常的检出率及准确率,并可有效检测der（9）缺失.

Objective To investigate the characteristics in cytogenetics and molecular genetics of chronic myeloid leukemia （CML） and the clinical significance of CML. Methods 196 patients with CML were selected. Bone marrow direct method and/or 24 h culture without phytohaemagglutimin were used to prepare the chromosomes and karyotype analysis was performed with R - banding techniques. Fluorescence in situ hybridization （FISH） with Dual colour/dual fusion or extra - signal （ES） DNA probe was used to detect BCR - ABL fusion gene in patients with CML. Results The patients were divided into chronic phase and accelerated phase/blast crisis. The cytogenetic results showed that the proportion of additional chromosome and variant translocation was 9/166 （5.4%） and 7/166 （4.2%） in chronic phrase, and 19/30 （63.3%） and 3/30 （10.0%） in accelerated phase/blast crisis. Among the 196 cases, 179 cases （91.3% ） were Ph positive in which classic translocation was found in 169 cases （94.4%）, variant translocation in 10 cases （5.6%） and the most common nmnerical abnormalities were double Ph, ＋ 8, i （17q） and -Y. By molecular genetic analysis, 68 cases underwent FISH determination and were BCR - ABL positive （ including 10 cases of variant transloca- tion, 11 cases with Ph negative chromosome and 6 cases with karyotype determination failure）, in which 10 cases （14.7%） were der （9） deletions including 1 case with chromosome and karyotype determination failure. The proportion was 8/55 （14.5%） and 2/13 （15.4%） in chronic phase group and accelerated/blast crisis group, respectively. Of the 68 cases, there were 41 cases of classic translocation, 10 cases of variant translocation, and the proportion of der （9） deletions in classic translocation and variant translocation was 5/41 （ 12.2% ） and 4/10 （40%）, respectively. Conclusion Compared to chronic phase, the incidences of additional chromosome and variant translocation are much higher in accelerated phase/blast crisis. Conventional cytogenetic analysis is helpful to the diagnosis of CML and analysis of the progress. On the basis of conventional cytogenetic analysis, FISH analysis technology can significantly promote the diagnosis rate and the accuracy in detection of chromosomal abnormalities, and is effective in the detection of der （9） deletions.