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.

How common is cyclic neutropenia (CyN)?

CyN is rare. There are an estimated 1-2 cases per 1 million people worldwide. The figure is estimated at 0.5 to 1 per 1 million people in the US.

Who is affected by cyclic neutropenia (CyN)?

The incidence is evenly split between male and female.

What causes cyclic neutropenia (CyN)?

CyN can occur later in life or be congenital (present from birth), but generally presents becomes evident right after birth. CyN is caused by a change in the genetic instructions (a mutation) to make an enzyme for fighting infection. Neutropenia symptoms result when the bone marrow does not produce enough neutrophils, when neutrophils die early, or when these cells do not perform correctly.

What are the symptoms of cyclic neutropenia (CyN)?

  • Fatigue
  • Fever
  • Sores in the mouth
  • Recurring gum problems and loose teeth
  • Sore throat
  • Skin infections
  • Lung infections
  • Digestive system infections
  • An overall feeling of not being well

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