Algorithm for the diagnosis of acquired neutropenia. “Anti-neutrophil antibody” is enclosed in parentheses to indicate that the test has limited utility (see text). abnl, abnormal; AML, acute myeloid leukemia; ANC, absolute neutrophil count; BMF, bone marrow failure; CBC, complete blood count; diff, differential count; Dx, diagnosis; Hx, history; Ig, immunoglobulins A, G, and M; LGL, large granular lymphocyte; MDS, myelodysplastic syndrome; NGS, next generation sequencing; Nl, normal; Sx, symptoms. “Severe phenotype” indicates severe, recurrent, or opportunistic infections. Adapted from Dinauer et al¹  with permission.