Severe Congenital Neutropenia (SCN)
What is severe congenital neutropenia?
Severe congenital neutropenia (SCN) is a rare condition that is characterized by a dangerously low number of neutrophils which is apparent at birth or soon after. Neutrophils are a type of white blood cell that are necessary to fight infection. Due to the low numbers of these cells, affected individuals experience recurrent, frequent infections.
What are the symptoms of severe congenital neutropenia?
The major symptom of SCN is recurrent infections, which most commonly affect the liver, lungs, and sinuses. Fevers and inflammation of the skin and gums are also symptoms, and some patients experience seizures, abnormalities of the genitals and heart, and developmental delay.
There are also complications that impact a portion of patients. Osteopenia is present in about 40% of cases, and it has the potential to advance to osteoporosis. 20% of patients go on to develop blood cancers, typically leukemia or myelodysplastic syndromes.
What causes severe congenital neutropenia?
There are a number of different genes that mutate to cause SCN, the most common of which is the ELANE gene. This is followed by the HAX1 gene, and then a number of other mutations that account for small portions of cases. Regardless of the mutation one has, it impacts the production or functioning of neutrophils, stopping them from performing as they normally would.
In terms of inheritance, it depends on which genetic mutation one has. Some cases are not even inherited; they are sporadic mutations. The ELANE gene is passed down in an autosomal dominant pattern, the HAX1 gene in an autosomal recessive pattern, and a number of other genes in an X-linked recessive pattern.
How is severe congenital neutropenia diagnosed?
Because the symptoms appear soon after birth, diagnosis soon follows. It begins with a physical exam and looking for the characteristic symptoms. A blood test and bone marrow testing can be used to find the number of neutrophils, and genetic testing can confirm.
What are the treatments for severe congenital neutropenia?
Treatment for this condition consists of preventing and treating infections. Doctors may use antibiotics, bone marrow transplants, anti-inflammatory drugs, and granulocyte-colony stimulating factor (G-CSF).