Fabry disease

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Fabry disease is an inherited disorder that results from the buildup of a type of fat, called globotriaosylceramide, in the body's cells. Beginning in childhood, this buildup causes signs and symptoms that affect many parts of the body. Characteristic features of Fabry disease include episodes of pain, particularly in the hands and feet (acroparesthesias); clusters of small, dark red spots on the skin called angiokeratomas; a decreased ability to sweat (hypohidrosis); cloudiness or streaks in the front part of the eye (corneal opacity or corneal verticillata); problems with the gastrointestinal system; ringing in the ears (tinnitus); and hearing loss. Additional signs and symptoms are possible, which can vary among affected individuals.

Fabry disease also involves potentially life-threatening complications such as progressive kidney failure, heart failure, and stroke. Some affected individuals have milder forms of the disorder that appear later in life and typically involve only the heart, kidneys, or blood vessels in the brain.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Fabry disease is caused by variants (also known as mutations) in the GLA gene. This gene provides instructions for making an enzyme called alpha-galactosidase A. This enzyme is active in lysosomes, which are structures that serve as recycling centers within cells. Alpha-galactosidase A normally breaks down a fatty substance called globotriaosylceramide. Variants in the GLA gene alter the structure and function of the enzyme, preventing it from breaking down this substance effectively. As a result, globotriaosylceramide builds up in cells throughout the body, particularly cells lining blood vessels in the skin and cells in the kidneys, heart, and nervous system. The progressive accumulation of this substance damages cells, leading to the varied signs and symptoms of Fabry disease.

GLA gene variants that result in an absence of alpha-galactosidase A activity lead to the classic, severe form of Fabry disease. Variants that decrease but do not eliminate the enzyme's activity usually cause the milder, late-onset forms of Fabry disease that typically affect only the heart, kidneys, or blood vessels in the brain.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an X-linked pattern. A condition is considered X-linked if the altered gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. In males (who have only one X chromosome), one altered copy of the GLA gene in each cell is sufficient to cause the condition. Because females have two copies of the X chromosome, one altered copy of the gene in each cell usually leads to less severe symptoms in females than in males, or rarely may cause no symptoms at all.

Unlike other X-linked disorders, Fabry disease causes significant medical problems in many females who have one altered copy of the GLA gene. These women may experience many of the classic features of the disorder, including nervous system abnormalities, kidney problems, chronic pain, and fatigue. They also have an increased risk of developing high blood pressure, heart disease, stroke, and kidney failure. The signs and symptoms of Fabry disease usually begin later in life and are milder in females than in their affected male relatives.

A small percentage of females who carry a variant in one copy of the GLA gene never develop signs and symptoms of Fabry disease.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Fabry disease affects an estimated 1 in 1,000 to 9,000 people. Milder, late-onset forms of the disorder are probably more common than the classic, severe form.

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.

Abdominal pain · Very frequent (99-80%)

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

Abnormal glycosphingolipid metabolism · Very frequent (99-80%)

An abnormality of glycosphingolipid metabolism.

Anemia · Very frequent (99-80%)

A reduction in erythrocytes volume or hemoglobin concentration.

Angiokeratoma · Very frequent (99-80%)

Angiokeratomas are hyperkeratotic papules that are characterized histologically by superficial ectatic (i.e., dilated) blood vessels with epidermal proliferation. Clinically, angiokeratoma presents as a small, raised, dark-red spot.

Arthralgia · Very frequent (99-80%)

Joint pain.

Arthritis · Very frequent (99-80%)

Inflammation of a joint.

Congestive heart failure · Very frequent (99-80%)

The presence of an abnormality of cardiac function that is responsible for the failure of the heart to pump blood at a rate that is commensurate with the needs of the tissues or a state in which abnormally elevated filling pressures are required for the heart to do so. Heart failure is frequently related to a defect in myocardial contraction.

Conjunctival telangiectasia · Very frequent (99-80%)

The presence of small (ca. 0.5-1.0 mm) dilated blood vessels near the surface of the mucous membranes of the conjunctiva.

Other findings in the same source

From: Orphanet

Additional reported features include Corneal dystrophy (Very frequent (99-80%)); Corneal opacity (Very frequent (99-80%)); Decreased alpha-galactosidase A activity (Very frequent (99-80%)); Elevated circulating globotriaosylceramide concentration (Very frequent (99-80%)); Fatigue (Very frequent (99-80%)); Hearing impairment (Very frequent (99-80%)); Hematuria (Very frequent (99-80%)); Hyperkeratosis (Very frequent (99-80%)); Hypohidrosis (Very frequent (99-80%)); Malabsorption (Very frequent (99-80%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Fabry disease is Metabolic Medicine, with a metabolic specialist / clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with metabolic specialist / clinical geneticist referral.

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.

• Is a biochemical or molecular result needed to clarify the diagnosis?
• Does this condition require an individual plan for illness or reduced food intake?
• Should nutrition advice come from a specialist metabolic dietitian?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Fabry disease. 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.