Juvenile Paget disease

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Juvenile Paget disease is a disorder that affects bone growth. This disease causes bones to be abnormally large, misshapen, and easily broken (fractured). The specific signs and symptoms and the severity of the condition can vary among affected individuals.

The features of juvenile Paget disease appear in infancy or childhood. As bones grow, they become weaker and misshapen. These abnormalities usually become more severe during the adolescent growth spurt, when bones grow very quickly.

Juvenile Paget disease affects the entire skeleton, resulting in widespread bone and joint pain. The bones of the skull tend to grow unusually large and thick, which can increase the size of the head (circumference). The abnormal growth of the skull bones can damage the bones in the ear, leading to hearing loss. The disease can also cause an abnormal curvature of the spine (kyphosis). Additionally, the weight-bearing long bones in the legs tend to bow and fracture easily, which can interfere with the ability to stand and walk.

Other features of juvenile Paget disease can include short stature; developmental delays; dental problems, such as the delayed appearance (eruption) of teeth or the early (premature) loss of teeth; and vision problems, which can include abnormalities of the light-sensing tissue at the back of the eye (retina). Affected individuals may also have an abnormal accumulation of calcium (calcification) in the walls of blood vessels. Rarely, people with juvenile Paget disease have a bulge (aneurysm) in the wall of the vessel that carries blood to the brain, face, and neck (internal carotid artery). If an aneurysm grows large, it can burst and cause dangerous bleeding.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Variants (also called mutations) in the TNFRSF11B gene cause juvenile Paget disease. This gene provides instructions for making a protein that is involved in bone remodeling, a normal process in which old bone is broken down and replaced by new bone. Bones are constantly being remodeled, and the process is carefully controlled to ensure that bones stay strong and healthy.

The variants in the TNFRSF11B gene that are associated with juvenile Paget disease cause cells to produce a version of the protein that does not function properly. As a result, bone is broken down and then replaced at a faster rate than usual. The new bone tissue is larger, less organized, and weaker than normal bone. This abnormally fast bone remodeling leads to the features seen in people with juvenile Paget disease.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

Juvenile Paget disease is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell must have a variant to cause the disorder. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Juvenile Paget disease is extremely rare; approximately 100 affected individuals have been reported in the medical literature.

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.

Abnormality of the clavicle · Very frequent (99-80%)

Any abnormality of the clavicles (collar bones).

Abnormality of the dentition · Very frequent (99-80%)

Any abnormality of the teeth.

Bowing of the long bones · Very frequent (99-80%)

A bending or abnormal curvature of a long bone.

Cranial hyperostosis · Very frequent (99-80%)

Excessive growth of the bones of cranium, i.e., of the skull.

Hyperuricemia · Very frequent (99-80%)

The concentration of uric acid in the blood circulation is above the upper limit of normal.

Macrocephaly · Very frequent (99-80%)

Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.

Osteoporosis · Very frequent (99-80%)

Osteoporosis is a systemic skeletal disease characterized by low bone density and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility. According to the WHO criteria, osteoporosis is defined as a BMD that lies 2.5 standard deviations or more below the average value for young healthy adults (a T-score below -2.5 SD).

Recurrent fractures · Very frequent (99-80%)

The repeated occurrence of bone fractures (implying an abnormally increased tendency for fracture).

Other findings in the same source

From: Orphanet

Additional reported features include Rough bone trabeculation (Very frequent (99-80%)); Short stature (Very frequent (99-80%)); Abnormality of retinal pigmentation (Frequent (79-30%)); Hearing impairment (Frequent (79-30%)); Hypertension (Frequent (79-30%)); Optic atrophy (Frequent (79-30%)); Pectus carinatum (Frequent (79-30%)); Melanocytic nevus (Occasional (29-5%)); Subcutaneous nodule (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 Juvenile Paget disease is Orthopaedics, with a orthopaedic specialist 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.

• What explains the change in pain, movement or function?
• Which activities need adjustment while the diagnosis is being clarified?
• What are the roles of rehabilitation, observation and surgery in this situation?

Treatment discussions and follow-up

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