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Disease Profile

Severe congenital neutropenia

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

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ICD-10

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Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
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Orpha Number: 42738

Definition
Severe congenital neutropenia is an immunodeficiency characterized by low levels of granulocytes (< 200/mm3) without an associated lymphocyte deficit.

Epidemiology
The prevalence in the general population is estimated at 1-1.7/333,300. Annual incidence is around 1/250,000 births.

Clinical description
This neutropenia leads to repeated bacterial or mycotic infections in various locations, mostly cutaneo-mucous, ear, nose, and throat, and pulmonary. Stomatological signs are almost always present after 2 years of age and are distinguished by erosive gingivitis, hemorrhage and pain, associated with papilla on the tongue and mucous membranes. Infections may be very severe or even lethal. Around 15% of patients evolve to acute leukemia or a myelodysplastic syndrome.

Etiology
To date, mutations in four genes have been implicated in severe congenital neutropenia. These include the neutrophil elastase gene (ELA2), the GFI1 gene, the HAX1 gene and activation genes of Wiskott Aldrich disease (WASP). The combination of these mutations leads to a deficit in the production of neutrophils.

Diagnostic methods
The defining characteristic is cytology showing profound neutropenia associated with monocytosis. An isolated blockage at the promyelocyte stage of the myeloid series associated with eosinophilia and monocytosis is seen on myelogram.

Differential diagnosis
On the discovery of these features a complete biological assessment should be conducted to rule out several differential diagnoses, particularly lymphocytic immune deficiencies and autoimmune neutropenia.

Antenatal diagnosis
Prenatal diagnosis may be offered if the genotype is known.

Genetic counseling
The four mutations are transmitted differently: ELA2 and GFI1 are autosomal dominant, HAX1 is autosomal recessive, and WASP is X-linked recessive. Genetic counseling is essential and should take into account family history and the causal mutation.

Management and treatment
All febrile episodes or infections should be reviewed by a hospital and treated actively. Prophylactic antibiotics are used to prevent infections. If this is ineffective, hematopoietic growth factors (G-CSF in particular) can correct both neutropenia and the susceptibility to infections and can be administered either in response to infections or continuously. The dose of G-CSF required varies greatly. Continuous high dose G-CSF (more than 20µg/kg/day) encourages the onset of leukemia in the long term and therefore, in cases requiring continuous high dose treatment, bone marrow transplant should be considered.

Prognosis
The prognosis depends heavily on the quality of care and timeliness of treatment of severe infections, but also on the possibility of a bone marrow transplant, particularly in cases with malignant transformation.

Visit the Orphanet disease page for more resources.

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • Online Mendelian Inheritance in Man (OMIM) lists the subtypes and associated genes for Severe congenital neutropenia in a table called Phenotypic Series. Each entry in OMIM includes a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.