This topic review discusses cyclic neutropenia (also called cyclic hematopoiesis), which, in contrast to other rare congenital neutropenias, tends to be mild and benign, but can occasionally be severe.
Other causes of neutropenia are discussed separately. (See "Overview of neutropenia in children" and "Congenital neutropenia".)
Cyclic neutropenia is a rare, autosomal dominantly inherited disorder with variable expression and an estimated incidence of one to two per million [1,2]. It is characterized by neutropenia that recurs every 14 to 35 days, although over 90 percent of patients exhibit a cycle period of 21 days . While the disease tends to be benign, several affected patients have died of infection . Most of the patients present in the first year of life.
There is an acquired adult onset form of cyclic neutropenia; however, it is autoimmune rather than genetic in nature and has been found in association with T cell large granular lymphocyte leukemia. (See "Clinical manifestations, pathologic features, and diagnosis of T cell large granular lymphocyte leukemia", section on 'Clinical features'.)
Cyclic neutropenia can be cured by hematopoietic cell transplantation in an animal model  and has been transferred from an affected human donor to a recipient following hematopoietic cell transplantation , demonstrating that this disorder is an intrinsic disorder of bone marrow stem cells.