- Neutropenia according to the cause: + Congenital neutropenia (Primary): Because of gene mutations +Acquired neutropenia (Secondary): Neutropenia after another disease. Acquired neutropenia are divided 2 groups: * Decreased production: Causes exert an influence on bone marrow leading to neutropenia: infection (virus, bacteria), blood 8 disease (acute leukemia, aplastic anemia, myelodysplastic syndrome), chemotherapy treats cancers.