Author contributions
WAS
S.S. performed phenotypic characterization, IS retrieval of HSPC progenitors and additional molecular testing for VCN estimation, performed in vitro and in vivo assays, collected and interpreted the data and wrote the manuscript. Fr.F. provided WAS patients’ BM and PB samples and clinical data, L.B.-R. performed phenotypic characterization and isolation of HSPC subpopulations, performed in vitro and in vivo assays and analyzed the data. F.D. performed LAM–PCR and VCN estimation for all BM and PB patient samples. M.O. mapped IS and performed capture and re-capture analyses, P.Q. performed in vitro and in vivo assays for primitive HSPC populations. R.J.H. performed in vivo assay; L.D.C. designed and applied statistical analyses to normalize IS data and performed the exploratory analyses to assess the impact of each variables to IS dataset. F.B. performed IS retrieval through SLIM-PCR; I.M. and S.Gi. performed isolation of patient cell lineages. Fe.F., S.D. and E.A. contributed to clinical trial management and support. S.Ga. performed statistical analyses on longitudinal patients’ samples. E.M. and A.C. supervised IS analyses and critically revised the manuscript. M.P.C. provided WAS patients’ BM and PB samples and clinical data. A.A. contributed as PI by interpreting data, supervising the project and revising the manuscript.