In this study, we showed that repair of the R736C mutation with CRISPR/Cas9 editing of patient derived induced pluripotent stem cells (iPSCs) corrected the defect in myelopoiesis, and modeled TCIRG1-associated neutropenia using patient derived iPSCs, and characterized the hematopoietic abnormalities through in vitro differentiation studies. This evidence concerns the gene TCIRG1 and Decreased total neutrophil count.