title: Deep sequencing reveals stepwise mutation acquisition in paroxysmal nocturnal hemoglobinuria.
abstract: 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 PIGA mutation. Together, our data indicate that in addition to PIGA mutations, accessory genetic events are frequent in PNH, suggesting a stepwise clonal evolution derived from a singular stem cell clone.
authors.forename: Wenyi
authors.initials: W
authors.lastname: Shen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Clemente
authors.forename: Naoko
authors.initials: N
authors.lastname: Hosono
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yoshida
authors.forename: Bartlomiej
authors.initials: B
authors.lastname: Przychodzen
authors.forename: Tetsuichi
authors.initials: T
authors.lastname: Yoshizato
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Shiraishi
authors.forename: Satoru
authors.initials: S
authors.lastname: Miyano
authors.forename: Seishi
authors.initials: S
authors.lastname: Ogawa
authors.forename: Jaroslaw P
authors.initials: JP
authors.lastname: Maciejewski
authors.forename: Hideki
authors.initials: H
authors.lastname: Makishima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D049308:Dioxygenases; D059472:Exome; D005260:Female; D005434:Flow Cytometry; D006457:Hemoglobinuria, Paroxysmal / Q000235:genetics*; D006461:Hemolysis; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D009363:Neoplasm Proteins; D009687:Nuclear Proteins / Q000235:genetics; D063151:Polycomb Repressive Complex 2 / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012261:Ribonucleoproteins / Q000235:genetics; D000072668:Splicing Factor U2AF; D014157:Transcription Factors; D055815:Young Adult
chemical_list: D004268:DNA-Binding Proteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012261:Ribonucleoproteins; C430461:SUZ12 protein, human; D000072668:Splicing Factor U2AF; D014157:Transcription Factors; C076753:U2AF1 protein, human; C080086:phosphatidylinositol glycan-class A protein; D049308:Dioxygenases; C541081:TET2 protein, human; D063151:Polycomb Repressive Complex 2; C507924:JAK2 protein, human; D053614:Janus Kinase 2