Genomics analysis of leukaemia predisposition in X‐linked agammaglobulinaemia

X-linked agammaglobulinemia (XLA) is an inborn error of immunity caused by pathogenic variants in Bruton’s tyrosine kinase (BTK). BTK plays important role B-cell differentiation, proliferation and survival, XLA patients display a differentiation arrest at the pro-B cell to pre-B transition.1 Several have been diagnosed with malignancies three large cohorts (summarized Table SI).2-4 It biologically plausible that may higher rates acute leukaemia. In genetic models, was found function as tumour suppressor: ablation Btk Blnk (Slp65) knockout mice leads accelerated development pre-B-cell leukaemia.5 The prevalence leukaemia approximately 2 per 300 Japan. epidemiological data, including previous reports, shown Data S1. Furthermore, cohort chronic lymphoid receiving inhibitors, occurrence secondary cancers, haematological malignancies, were observed.6 We previously reported two precursor lymphoblastic (BCP-ALL).7, 8 order identify contribution germline mutation malignant predisposition, we here analyzed leukaemic cells for somatic mutations, copy number alterations DNA methylation profile using next-generation sequencing these one newly identified patient megakaryoblastic (AMKL). clinical laboratory data are described SII, Figure S1 First, non-synonymous gene cells. Following whole-exome (WES) on paired genomic samples, 13, 7 5 1, 3 respectively (Table I). A heterozygous missense variant KMT2D/MLL2 (c.8740delC, p.H2914Tfs*29) (variant allele frequency (VAF): 0·47) splice site CDKN2A (c.193+5G>A) (VAF: 0·36) pathologic 1. KMT2D has inactive recurrent non-Hodgkin lymphomas.9 hereditary cancer-predisposing syndrome.10 2, KMT2C (c.2294A>G, p.E765G) 0·15), TP53 (c.818G>A, p.R273H) 0·81) TCF3 (c.359T>C, p.L120P) 0·31) identified. oncogenic abnormalities histone methylation.11 most common suppressor genes. R273H dominant negative variant.12 crucial lymphocyte case severe hypogammaglobulinemia BCP-ALL reported.13 Heterozygous FOXM1 (c.1208G>A, p.R403H) 0·03) NSD1 (c.6656G>A, p.R2219H) 0·17) 3. transcription factor associated cycle proliferation.14 also All variants, except TCF3, involved signaling pathway, epigenetic regulation suppression, but not maturation. acquired loss (LOF) suppressors (CDKN2A monosomy 7). To evaluate if (L120P) potentially leukaemogenesis, functional analysis target binding performed luciferase assay. Although disease control (E555K) showed lower activity compared WT (P < 0·01), L120P mutant efficient = 0·07) (Figure S2). Thus, does appear result LOF TCF3. further 1 2. Somatic amplification ERG 21q22.2 detected S3A). event various leukaemias.15 Consistent finding G-banding karyotype, amplifications observed chromosomes 6, 10, 11, 12, 14, 18, 19, 21, 22, X Y SII S3B). profiles did show distinctive profile. No hypermethylation status (e.g. CASP8AP2) S4). recent years, leukaemogenic five classes proteins: pathway components, factors, regulators, components spliceosome.16 mutations registered COSMIC database (https://cancer.sanger.ac.uk/cosmic). aberrant without encoded truncated domain.17 Reconstitution expression induced apoptosis which impair pre-BCR B GM-CSF-mediated myeloid progenitor cells, might induce maturation megakaryoblasts respectively.18 Moreover, impairs pathways proliferation. Therefore, presume driver second hits, promote leukaemogenesis patients. As described, Btk/p53-deficient increased proliferative capacity immature cells.19 our study, all suppressors, suggesting mutation-induced first hit hit, ultimately leading evolution clonal models Fig These findings would be inhibitor treatment. suggest need closer more systematic follow-up From perspective precision medicine, who acquire candidates haematopoietic transplantation pre-emptive therapy. limitation this study evaluated only perform non-coding regions because limited samples. Future studies many leukemia enrolled able clarify detailed characteristics XLA. authors thank families Ms. Mika Nagase, Mr. Wataru Iguchi, Naomi Terada-Takahashi their technical assistance. This work supported MEXT/JSPS KAKENHI (Grant Number: JP17K10099) HK, AMED practical Research Innovative Cancer Control (19ck0106467h0001) TM. Akira Nishimura, Menno C. van Zelm Hirokazu Kanegane designed wrote manuscript. Takuya Naruto, Akihiro Hoshino Osamu Ohara genomics analysis. Nishimura Satoshi Miyamoto Andrew Grigg, Julian J. Bosco, Keishiro Amano, Shotaro Iwamoto, Masahiro Hirayama Migita provided care. Masatoshi Takagi Tomohiro Morio critical discussion. Supplementary Data. SI. Literature review SII. Clinical Pathological immunophenotypic S2. Luciferase assay S3. Copy variants. S4. Please note: publisher responsible content or functionality any supporting information supplied authors. Any queries (other than missing content) should directed corresponding author article.