Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome primarily affects males and is caused by problems with the immune system. The immune system normally protects the body from foreign invaders, such as bacteria and viruses, by recognizing and attacking these invaders and clearing them from the body. However, the immune system can malfunction and attack the body's own tissues and organs instead, which is known as autoimmunity. IPEX syndrome is characterized by the development of multiple autoimmune disorders in affected individuals. Although IPEX syndrome can affect many different areas of the body, autoimmune disorders involving the intestines, skin, and hormone-producing (endocrine) glands occur most often. IPEX syndrome can be life-threatening in early childhood.

Almost all individuals with IPEX syndrome develop a disorder of the intestines called autoimmune enteropathy. Autoimmune enteropathy occurs when certain cells in the intestines are destroyed by a person's immune system. It causes severe diarrhea, which is usually the first symptom of IPEX syndrome. Autoimmune enteropathy typically begins in the first few months of life. It can lead to an inability to gain weight and grow at the expected rate (faltering weight) and general wasting and weight loss (cachexia).

People with IPEX syndrome frequently develop inflammation of the skin, called dermatitis. Eczema is the most common type of dermatitis that occurs in this syndrome, and it causes abnormal patches of red, irritated skin. Other skin disorders that cause similar symptoms are sometimes present in IPEX syndrome.

The term polyendocrinopathy is used in IPEX syndrome because individuals can develop multiple disorders of the endocrine glands. Type 1 diabetes mellitus is an autoimmune condition involving the pancreas and is the most common endocrine disorder present in people with IPEX syndrome. It usually develops within the first few months of life and prevents the body from properly controlling the amount of sugar in the blood. Autoimmune thyroid disease may also develop in people with IPEX syndrome. The thyroid gland is a butterfly-shaped organ in the lower neck that produces hormones. This gland is commonly underactive (hypothyroidism) in individuals with this disorder, but may become overactive (hyperthyroidism).

Individuals with IPEX syndrome typically develop other types of autoimmune disorders in addition to those that involve the intestines, skin, and endocrine glands. Autoimmune blood disorders are common; about half of affected individuals have low levels of red blood cells (anemia), platelets (thrombocytopenia), or certain white blood cells (neutropenia) because these cells are attacked by the immune system. In some individuals, IPEX syndrome involves the liver and kidneys.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Mutations in the FOXP3 gene cause IPEX syndrome. The protein produced from this gene is a transcription factor, which means that it attaches (binds) to specific regions of DNA and helps control the activity of particular genes. This protein is essential for the production and normal function of certain immune cells called regulatory T cells. Regulatory T cells play an important role in controlling immune responses and preventing autoimmune disorders. Mutations in the FOXP3 gene impair the normal function of regulatory T cells, making it difficult for the body to turn off immune responses when they are not needed. Normal body tissues and organs are attacked, causing the multiple autoimmune disorders that develop in people with IPEX syndrome.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

IPEX syndrome is inherited in an X-linked recessive pattern. The FOXP3 gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

Some people have conditions that appear identical to IPEX syndrome, but they do not have mutations in the FOXP3 gene. These conditions do not follow an X-linked inheritance pattern, and females can be affected. Such conditions are classified as IPEX-like syndromes.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

IPEX syndrome is a rare disorder that affects an estimated 1 in 1.6 million people.

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.

Autoimmunity · Very frequent (99-80%)

The occurrence of an immune reaction against the organism's own cells or tissues.

Abnormal blood ion concentration · Frequent (79-30%)

Abnormality of the homeostasis (concentration) of a monoatomic ion.

Abnormal intestine morphology · Frequent (79-30%)

An abnormality of the intestine. The closely related term enteropathy is used to refer to any disease of the intestine.

Abnormality of the endocrine system · Frequent (79-30%)

An abnormality of the endocrine system.

Allergy · Frequent (79-30%)

An allergy is an immune response or reaction to substances that are usually not harmful.

Anti-thyroid peroxidase antibody positivity · Frequent (79-30%)

The presence of autoantibodies (immunoglobulins) in the serum that react against thyroid peroxidase.

Eczematoid dermatitis · Frequent (79-30%)

Eczema is a form of dermatitis that is characterized by scaly, pruritic, erythematous lesions located on flexural surfaces.

Eczematoid dermatitis · Frequent (79-30%)

Eczema is a form of dermatitis that is characterized by scaly, pruritic, erythematous lesions located on flexural surfaces.

Other findings in the same source

From: Orphanet

Additional reported features include Increased circulating IgE concentration (Frequent (79-30%)); Inflammatory abnormality of the skin (Frequent (79-30%)); Reduced proportion of CD4-negative, CD8-negative, alpha-beta regulatory T cells (Frequent (79-30%)); Secretory diarrhea (Frequent (79-30%)); Thyroiditis (Frequent (79-30%)); Type I diabetes mellitus (Frequent (79-30%)); Crusting erythematous dermatitis (Frequent (79-30%)); Failure to thrive in infancy (Frequent (79-30%)); Iron deficiency anemia (Frequent (79-30%)); Abnormal blistering of the skin (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome 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 Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome. 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.

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.