Laboratory of Molecular Biology and Cytogenetics, Department of Hematology, Blood Neoplasms and Bone Marrow Transplantation, Wroclaw Medical University, Wrocław, Poland.
Department of Hematology, Blood Neoplasms and Bone Marrow Transplantation, Wroclaw Medical University, Wrocław, Poland.
BMC Med Genomics. 2022 Feb 5;15(1):20. doi: 10.1186/s12920-022-01169-0.
Acute lymphoblastic leukemia is the most common type of cancer in children. Most often it affects the age group between 2 and 5 years of age. Studies have shown an improvement in general survivability, more than 90% 5-year overall survival (OS). Current treatment protocols for acute lymphoblastic leukemia require verification of the presence of favorable and unfavorable genetic abnormalities, which help qualify patients to the appropriate risk group and select a more suitable treatment. The presence of the BCR/ABL1 fusion gene stratifies the patient into a high-risk group and requires special treatment with tyrosine kinase inhibitors (TKI). The three dominant mRNA transcripts are e1a2, e13a2, and e14a2. Nevertheless, cases of atypical BCR/ABL1 transcripts have also been reported.
This paper presents the case of a pediatric patient with Ph + B-cell precursor acute lymphoblastic leukemia with rare atypical e8a2 BCR/ABL1 fusion transcript. Our patient achieved complete remission after 33 days of treatment. Molecular and cytogenetic studies in TP1 did not reveal the presence of the BCR/ABL1 transcript. The PCR-MRD test in TP1b was negative, the patient did not require hematopoietic stem cell transplantation.
Genetic evaluation of the bone marrow sample is crucial in the initial stage of the diagnosis. Fluorescent in situ hybridization and reverse transcriptase polymerase chain reaction with Sanger sequencing are the appropriate methods used in the detection of rare variants of BCR/ABL1 transcripts.
急性淋巴细胞白血病是儿童中最常见的癌症类型。它通常影响 2 至 5 岁年龄段的儿童。研究表明，总体生存率有了显著提高，超过 90%的患者在 5 年内生存。目前治疗急性淋巴细胞白血病的方案需要验证是否存在有利和不利的遗传异常，这有助于将患者分为适当的风险组，并选择更合适的治疗方法。BCR/ABL1 融合基因的存在将患者分为高危组，并需要使用酪氨酸激酶抑制剂（TKI）进行特殊治疗。三个主要的 mRNA 转录本是 e1a2、e13a2 和 e14a2。然而，也有报道称存在非典型的 BCR/ABL1 转录本。
本文报告了一例 Ph+ 前体细胞 B 细胞急性淋巴细胞白血病伴罕见非典型 e8a2 BCR/ABL1 融合转录本的儿科患者。我们的患者在治疗 33 天后达到完全缓解。TP1 中的分子和细胞遗传学研究未发现 BCR/ABL1 转录本的存在。TP1b 中的 PCR-MRD 检测为阴性，患者无需进行造血干细胞移植。
在诊断的初始阶段，对骨髓样本进行基因评估至关重要。荧光原位杂交和 Sanger 测序的逆转录聚合酶链反应是检测 BCR/ABL1 转录本罕见变异的适当方法。
