What is cyclic neutropenia (CyN)?

What is cyclic neutropenia (CyN)?

Neutropenia refers to lower-than-normal levels of neutrophils in the blood. A neutrophil (also known as a granulocyte or polymorphonuclear leukocyte) is a type of white blood cell produced in the bone marrow. White blood cells in general, and neutrophils in particular, are important for infection control in the body. A shortage of neutrophils render a person susceptible to infection.

Cyclic neutropenia (CyN) is not present all of the time. The number of circulating neutrophils decreases and normalizes on a regular basis. It is also called periodic neutropenia or cyclic hematopoiesis.

The periods of neutropenia typically last 3 to 5 days. The periods return every 14-35 days, often around 21 days.