Deep sequencing reveals stepwise mutation acquisition in paroxysmal nocturnal hemoglobinuria
Deep sequencing reveals stepwise mutation acquisition in paroxysmal nocturnal hemoglobinuria
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DOI：
10.1172/jci74747
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发表时间：
2014-10-01
影响因子：
15.9
通讯作者：
Makishima, Hideki
中科院分区：
文献类型：
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作者：
Shen, Wenyi;Clemente, Michael J.;Makishima, Hideki
阵发性睡眠性血红蛋白尿症（PNH）是一种与溶血、骨髓衰竭和血栓形成倾向相关的造血干细胞非恶性克隆性疾病。PNH被认为是由编码PIGA的基因中的体细胞突变引起的单基因疾病，PIGA是糖基磷脂酰肌醇锚定（GPI锚定）蛋白的生物合成所必需的。某些GPI锚定蛋白的丢失被假设为突变克隆提供了外在的生长优势，但PNH的一些特征认为克隆扩张有内在的驱动因素。在这里，我们对取自12名患者的样本进行了成对PNH+和PNH-组分的全外显子组测序，并对另外36名PNH患者进行了靶向深度测序。我们发现了额外的体细胞突变，导致复杂的分层克隆结构，类似于在骨髓肿瘤中观察到的。除PIGA突变外，已知参与髓系肿瘤发病机制的基因中也发现了突变，包括TET2、SUZ12、U2AF1和JAK2。克隆分析表明，这些额外的突变出现作为一个亚克隆内的PIGA突变群体，或PICA突变之前。总之，我们的数据表明，除了PICA突变，辅助遗传事件是频繁的PNH，这表明一个逐步克隆进化来自一个单一的干细胞克隆。
Paroxysmal nocturnal hemoglobinuria (PNH) is a nonmalignant clonal disease of hematopoietic stem cells that is associated with hemolysis, marrow failure, and thrombophilia. PNH has been considered a monogenic disease that results from somatic mutations in the gene encoding PIGA, which is required for biosynthesis of glycosylphosphatidylinisotol-anchored (GPI-anchored) proteins. The loss of certain GPI-anchored proteins is hypothesized to provide the mutant clone with an extrinsic growth advantage, but some features of PNH argue that there are intrinsic drivers of clonal expansion. Here, we performed whole-exome sequencing of paired PNH+ and PNH- fractions on samples taken from 12 patients as well as targeted deep sequencing of an additional 36 PNH patients. We identified additional somatic mutations that resulted in a complex hierarchical clonal architecture, similar to that observed in myeloid neoplasms. In addition to mutations in PIGA, mutations were found in genes known to be involved in myeloid neoplasm pathogenesis, including TET2, SUZ12, U2AF1, and JAK2. Clonal analysis indicated that these additional mutations arose either as a subclone within the PIGA-mutant population, or prior to PICA mutation. Together, our data indicate that in addition to PICA mutations, accessory genetic events are frequent in PNH, suggesting a stepwise clonal evolution derived from a singular stem cell clone.