Marrow examinations show a range of abnormalities from "maturation arrest" at the promyelocyte stage to nearly complete maturation of the neutrophilic series.
Who distinctive groups of patients with severe congenital neutropenia have a relative abundance of marrow neutrophils with severe reductions in patients with glycogen storage type 1B, maturation of marrow neutrophils appears to be complete, but blood counts are very low and a similar pattern of infections and inflammation occur as in the older congenital neutropenias.