Infants with<unk>  have frequent infections: 50% have a significant infection within 1 month, most others by 6 months. Their etiology is usually bacterial, especially staphylococcal, and they commonly involve abscesses, both cutaneous and of internal organs, pneumonia, mastoiditis (inflammation of the mastoid process), and sepsis. All of these are life-threatening for infants.
Severe congenital neutropenia
Autoimmune neutropenia
Bare lymphocyte syndrome
Diffuse infiltrative lymphocytosis syndrome
Adult-onset immunodeficiency syndrome
Refractory cytopenia of childhood
Leukocyte adhesion deficiency
Myelodysplastic syndrome