MYB 或 MYBL1 基因组反复发生改变的星形细胞瘤是一组儿童型弥漫性低级别胶质瘤，在 2021 年 WHO 中枢神经系统肿瘤分类中新被认可。这些肿瘤在 WHO 分类中被描述为含有 MYB 或 MYBL1 融合。在本报告中，我们检查了 14 个连续的 MYB 或 MYBL1 改变病例，每个病例均通过全基因组 DNA 甲基化分析进行诊断确认（6 例血管中心神经胶质瘤和 8 例弥漫性星形细胞瘤，MYB 或 MYBL1 改变），以了解其具体情况这些基因的基因组改变。使用 RNA 测序，我们发现仅 5/14 的病例中 MYB 或 MYBL1 基因产生高效的框内融合。其余 9 例显示基因组改变导致基因截断，但没有框内融合伴侣的证据。基因表达分析显示，无论是否存在高效融合，MYB(L1) 基因均过度表达。此外，与包含超过 1000 个不同类型 CNS 肿瘤的队列相比，QKI（血管中心神经胶质瘤中常见的公认融合伙伴）在这 14 例中普遍上调，无论 QKI 是否存在基因组改变。总体而言，结果表明，在没有有效融合的情况下，MYB（L1）基因的截断可能会驱动肿瘤，并对血管中心性神经胶质瘤和弥漫性星形细胞瘤（MYB-或MYBL1-改变）的分析和诊断具有影响，特别是对于在专门用于融合检测的面板上进行测试的情况。© 2024。这是美国政府的作品，在美国不受版权保护；可能适用外国版权保护。

Astrocytomas that harbor recurrent genomic alterations in MYB or MYBL1 are a group of Pediatric-type diffuse low-grade gliomas that were newly recognized in the 2021 WHO Classification of Tumors of the Central Nervous System. These tumors are described in the WHO classification as harboring fusions in MYB or MYBL1. In this report, we examine 14 consecutive cases in which a MYB or MYBL1 alteration was identified, each with diagnostic confirmation by genome-wide DNA methylation profiling (6 Angiocentric gliomas and 8 Diffuse astrocytomas, MYB- or MYBL1-altered), for their specific genomic alterations in these genes. Using RNA sequencing, we find productive in-frame fusions of the MYB or MYBL1 genes in only 5/14 cases. The remaining 9 cases show genomic alterations that result in truncation of the gene, without evidence of an in-frame fusion partner. Gene expression analysis showed overexpression of the MYB(L1) genes, regardless of the presence of a productive fusion. In addition, QKI, a recognized fusion partner common in angiocentric glioma, was generally up-regulated in these 14 cases, compared to a cohort comprising >1000 CNS tumors of various types, regardless of whether a genomic alteration in QKI was present. Overall, the results show that truncations, in the absence of a productive fusion, of the MYB(L1) genes can likely drive the tumors and have implications for the analysis and diagnosis of Angiocentric glioma and Diffuse astrocytoma, MYB- or MYBL1-altered, especially for cases that are tested on panels designed to focus on fusion detection.© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.