Severe congenital neutropenia is a rare type of neutropenia that is present at birth. It is generally an inherited disease caused by a genetic mutation. Therefore, more than one family member can be affected, but sporadic occurrence with only one patient in a family is also possible. Prenatal genetic diagnosis may be available in families in which the specific gene mutation has been identified. Congenital neutropenia is usually very severe and neutrophils are often completely absent in the blood of these patients at the time of diagnosis. Patients who are diagnosed with congenital neutropenia usually show a maturation arrest in the early stages of neutrophil development in the bone marrow. This means that their neutrophils rarely fully mature into the cells that are capable of fighting infections.
These patients suffer from severe bacterial infections, such as omphalitis (infection of the umbilical stump), pneumonia or skin abscesses during their first few months of life. Therefore, in most patients congenital neutropenia is diagnosed during infancy. However, some patients present later in childhood. Blood tests and a bone marrow sample are required in order to obtain a correct diagnosis.