Autosomal dominant severe congenital neutropenia

What it is

From: Orphanet

A rare primary immunodeficiency disorder characterized by autosomal dominant inheritance, absolute neutrophil counts below 0.5x10E9/L in the peripheral blood (on three separate occasions over a six month period), granulopoiesis maturation arrest at the promyelocyte/myelocyte stage and early-onset, severe, recurrent bacterial infections.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Decreased total neutrophil count · Obligate (100%)

Abnormal decrease of absolute number of neutrophils in the blood, per microlitre, compared to a reference range for a given sex and age-group.

Recurrent bacterial infections · Very frequent (99-80%)

Increased susceptibility to bacterial infections as manifested by recurrent episodes of bacterial infection.

Recurrent viral infections · Very frequent (99-80%)

Increased susceptibility to viral infections as manifested by recurrent episodes of viral infection.

Abdominal pain · Frequent (79-30%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) and perceived to originate in the abdomen.

Diarrhea · Frequent (79-30%)

Abnormally increased frequency (usually defined as three or more) loose or watery bowel movements a day.

Fever · Frequent (79-30%)

Body temperature elevated above the normal range.

Gingivitis · Frequent (79-30%)

Inflammation of the gingiva

Increased total monocyte count · Frequent (79-30%)

Abnormal increase of absolute number of monocytes in the blood, per microlitre, compared to a reference range for a given sex and age-group.

Lymphopenia · Frequent (79-30%)

A reduced number of lymphocytes in the blood.

Oral ulcer · Frequent (79-30%)

Erosion of the mucous mebrane of the mouth with local excavation of the surface, resulting from the sloughing of inflammatory necrotic tissue.

Periodontitis · Frequent (79-30%)

Inflammation of the periodontium.

Pharyngitis · Frequent (79-30%)

Inflammation (due to infection or irritation) of the pharynx.

Pneumonia · Frequent (79-30%)

Inflammation of any part of the lung parenchyma.

Recurrent aphthous stomatitis · Frequent (79-30%)

Recurrent episodes of ulceration of the oral mucosa, typically presenting as painful, sharply circumscribed fibrin-covered mucosal defects with a hyperemic border.

Other findings in the same source

From: Orphanet

Additional reported features include Recurrent ear infections (Frequent (79-30%)); Recurrent infection of the gastrointestinal tract (Frequent (79-30%)); Recurrent sinopulmonary infections (Frequent (79-30%)); Recurrent skin infections (Frequent (79-30%)); Rhinitis (Frequent (79-30%)); Acute lymphoblastic leukemia (Occasional (29-5%)); Acute myeloid leukemia (Occasional (29-5%)); Antineutrophil antibody positivity (Occasional (29-5%)); Aplastic anemia (Occasional (29-5%)); Cellulitis (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Infancy; Neonatal

Inheritance in the source

From: Orphanet

Autosomal dominant

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal dominant pattern means that one altered copy of a relevant gene can be sufficient for the condition. Some affected people inherit the change; others have a new change without an affected parent. The precise finding, family history and condition determine what this means for relatives.

Which doctor should you see?

The suggested department for discussing Autosomal dominant severe congenital neutropenia is Allergy and Immunology, with a allergist / clinical immunologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Does the history suggest an allergy, an immune problem or another explanation?
• How would any proposed allergy or immune test change care?
• Is an individual emergency plan needed, and who should understand it?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Autosomal dominant severe congenital neutropenia. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.