WAS and X-linked severe congenital neutropenia: The WAS gene encodes a cytosolic protein known as WAS protein (WASp) and it expressed in myeloid, lymphoid, and hematopoietic stem cells (HSCs), which can lead to various clinical manifestations, but thrombocytopenia (X-linked thrombocytopenia [XLT]), eczema, and recurrent infections with increased risk of lymphoid malignancies, autoimmune disorders or congenital neutropenia (X-lined neutropenia [XLN]) are classic phenotype of WAS [40, 41].