Overview of Severe Congenital Neutropenia

Severe congenital neutropenia describes a condition where an individual is born with severe neutropenia (defined as neutrophil count < 500 cells per microliter, often < 200). One specific form is called Kostmann Syndrome. It is a rare condition affecting 2 -3 people for every one million people. 

Scientist reviewing bone marrow slides

Huntstock / Creative RF / Getty Images


Symptoms generally start shortly after birth. Neutrophils are a type of white blood cell that fights bacterial infections. The severely low neutrophil count increases your risk of bacterial infections. Fever is also a common symptom, but this is due to the infection not the neutropenia. Birth defects are generally not seen. Symptoms may include:

  • Otitis media (ear infections)
  • Cellulitis (skin infection)
  • Oral ulcers
  • Gingivitis (gum inflammation)


It is likely that during one of these infections, your doctor will obtain a complete blood count (CBC). Severe neutropenia (< 500 cells/microliter) should be the only blood cell affected. The red blood cells and platelets should be normal. Usually the monocytes — another type of white blood cell — will be elevated. If more than one type of blood cell is affected, other diagnoses (like Shwachman Diamond Syndrome) should be considered. 

Once the severe neutropenia is identified, your doctor may consider referring you to a hematologist, a doctor specializing in blood disorders. Initially, you may have a CBC drawn 2 to 3 times weekly to rule out cyclic neutropenia (a more benign condition) as the cause. 

The next step is a bone marrow biopsy. This test involves removing a small piece of bone from your hip to assess the bone marrow, the area where white blood cells are made. In severe congenital neutropenia, the cells are made normally initially but then at some point, they die before being released into circulation. 

If your bone marrow is consistent with severe congenital neutropenia, your doctor will likely send genetic testing to determine the particular mutation you have. This is important as it will determine if or how you might pass this condition on to your children. 


  • Granulocyte Colony Stimulating Factor (G-CSF or filgrastim): G-SCF is given as subcutaneous (under the skin) injections daily. This medication stimulates bone marrow production and maturation of neutrophils. The goal is to bring the neutrophil count to normal consistently to prevent infections.
  • Bone marrow transplantation: Bone marrow transplantation can be curative. This is usually considered for people with poor response to G-CSF. If receiving a bone marrow transplant from a sibling, it is important to make sure they do not have a milder form of severe congenital neutropenia. 
  • Antibiotics: If you have severe congenital neutropenia and develop a fever, you should seek immediate medical attention. Fever may be the only symptom of a serious infection. Blood work should be sent to identify a possible cause of infection. During this time you will be placed on IV (through the vein) antibiotics in case you have an infection. 

Are There Any Long Term Concerns? 

With better treatment, the life expectancy for people with severe congenital neutropenia has improved greatly. With increasing age, you are at increased risk for myelodysplastic syndrome (MDS) and leukemia (mostly acute myeloid leukemia) compared to the general population. This risk was thought to be secondary to G-CSF treatment but appears to be a complication of the condition. 

Treatment with G-CSF may result in splenomegaly (enlargement of the spleen). Occasionally this increase in spleen size will cause low platelet count (thrombocytopenia). If the thrombocytopenia is severe, you may require a splenectomy.  

Was this page helpful?