recurrent infections by Staphylococcus aureus and Gram-negative bacteria being the most life-threatening. Neutropenia may be classified as mild, moderate or severe in terms of numbers in the peripheral blood, and intermittent, cyclic, or chronic in terms of duration. Besides well-known classic severe congenital neutropenia, chronic neutropenia appears to be associated with an increasing number of primary immunodeficiency diseases (PIDs), including those of myeloid and lymphoid lineage. A comprehensive overview of the diverse clinical presenting symptoms, classification, aetiological and genetic etiologies of chronic isolated and syndromic neutropenia is aimed to be reviewed. |