METHODS: A child with B-ALL who has a MEF2C::SS18L1 fusion is reported as a newly discovered case. Compared the breakpoints, structural domains, clinical phenotypes, and differential expression genes of MEF2C::SS18L1 and MEF2D::SS18.Using \"ONCOFUSE\" software, the carcinogenicity of MEF2C::SS18L1 is predicted. Using whole transcriptome sequencing, we analyze the breakpoints and the secondary structure of the fusion protein. Further, we compared the structures, differentially expressed genes, and clinical phenotypes of MEF2D and MEF2C fusion genes by DESeq, GO functional enrichment, and flow cytometry immunophenotyping analysis.
RESULTS: Whole transcriptome sequencing identified a MEF2C::SS18L1 fusion transcript in a 3-year-old child with B-ALL. The MADS box, MEF structural domain, HJURP_C structural domain, and TAD I structural domain of MEF2C, and the QPGY structural domain of SS18L1, make up the fusion protein. \"Oncofuse\" found a 0.99 Bayesian probability that the fusion gene drives cancer. The breakpoint positions, fusion protein secondary structures, differentially expressed genes, and clinical characteristics of this patient were identical to those with MEF2D::SS18 fusion gene.
CONCLUSIONS: We identified a novel MEF2C::SS18L1 fusion gene in childhood ALL, which shares similar structural and clinical characteristics with MEF2D::SS18. Further studies with more samples should be conducted in future.
方法:报道了一例新发现的MEF2C::SS18L1融合的B-ALL患儿。比较断点,结构域,临床表型,MEF2C::SS18L1和MEF2D::SS18的差异表达基因。使用“ONCOFUSE”软件,预测了MEF2C::SS18L1的致癌性。使用全转录组测序,我们分析了融合蛋白的断点和二级结构。Further,我们比较了结构,差异表达基因,和MEF2D和MEF2C融合基因的临床表型,GO功能富集,和流式细胞术免疫表型分析。
结果:全转录组测序鉴定了一个3岁B-ALL患儿的MEF2C::SS18L1融合转录本。MADS盒子,MEF结构域,HJURP_C结构域,和MEF2C的TADI结构域,和SS18L1的QPGY结构域组成融合蛋白。“Oncofuse”发现融合基因驱动癌症的贝叶斯概率为0.99。断点位置,融合蛋白二级结构,差异表达基因,该患者的临床特征与MEF2D::SS18融合基因相同。
结论:我们在儿童ALL中发现了一个新的MEF2C::SS18L1融合基因,与MEF2D::SS18具有相似的结构和临床特征。将来应该进行更多样本的进一步研究。