Utsumi Sae, Shima Takahiro, Kubara Chiaki, Semba Yuichiro, Hayashi Masayasu, Takigawa Ken, Yoshino Teruhiko, Minami Mariko, Matsuo Yayoi, Kuriyama Takuro, Akashi Koichi, Maeda Takahiro, Taniguchi Shuichi, Eto Tetsuya
Department of Hematology, Hamanomachi Hospital.
Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences.
Rinsho Ketsueki. 2023;64(12):1503-1507. doi: 10.11406/rinketsu.64.1503.
A 27-year-old woman with pancytopenia was admitted to our hospital. Bone marrow aspiration revealed 52.2% myeloperoxidase-positive myeloblasts, leading to a diagnosis of acute myeloid leukemia. While a screening test for chimeric genes related to leukemia initially yielded negative results, including for the CBFB::MYH11 fusion gene, G-banded karyotyping uncovered the presence of inv (16)(p13.1q22). Further investigation by fluorescence in situ hybridization (FISH) confirmed the split signals for CBFB. A second screening test for leukemia-related chimeric genes with different PCR primers revealed the elusive CBFB::MYH11 fusion gene. Subsequently, the type I CBFB::MYH11 fusion gene was identified through exhaustive exploration using RNA sequencing for fusion gene discovery. This exceptional case highlights the existence of a distinctive subtype of CBFB::MYH11 that may yield false-negative results in conventional chimeric fusion screening, thus emphasizing the indispensable utility of PCR primer modification, FISH, and RNA sequencing in the investigative process.
一名患有全血细胞减少症的27岁女性入住我院。骨髓穿刺显示52.2%的髓过氧化物酶阳性原始粒细胞，诊断为急性髓系白血病。虽然最初对与白血病相关的嵌合基因进行的筛查测试结果均为阴性，包括CBFB::MYH11融合基因，但G带核型分析发现存在inv(16)(p13.1q22)。通过荧光原位杂交(FISH)进一步检测证实了CBFB的分裂信号。使用不同PCR引物对白血病相关嵌合基因进行的第二次筛查测试发现了难以捉摸的CBFB::MYH11融合基因。随后，通过使用RNA测序进行融合基因发现的详尽探索，鉴定出了I型CBFB::MYH11融合基因。这个特殊病例凸显了一种独特的CBFB::MYH11亚型的存在，这种亚型在传统嵌合融合筛查中可能产生假阴性结果，从而强调了PCR引物修饰、FISH和RNA测序在调查过程中不可或缺的作用。
