Multiple epiphyseal dysplasia due to collagen 9 anomaly

What it is

From: Orphanet

Multiple epiphyseal dysplasia due to collagen 9 anomaly is a rare primary bone dysplasia disorder characterized by normal or mild short stature, early-onset pain and/or stiffness of the joints (mainly affecting knees but also elbows, wrists, ankles and fingers, with relative sparing of the hips) and early degenerative joint disease. Other skeletal anomalies (incl. varus or valgus deformities, osteochondritis dissecans, abnormal carpal shape, free articular bodies) and mild myopathy have also been reported.

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 epiphysis morphology · Very frequent (99-80%)

An anomaly of epiphysis, which is the expanded articular end of a long bone that developes from a secondary ossification center, and which during the period of growth is either entirely cartilaginous or is separated from the shaft by a cartilaginous disk.

Arthralgia of the hip · Frequent (79-30%)

Joint pain affecting the hip.

Knee pain · Frequent (79-30%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) localized to the knee.

Limb undergrowth · Frequent (79-30%)

Limb shortening because of underdevelopment of one or more bones of the extremities.

Postexertional malaise · Frequent (79-30%)

Post-exertional symptom exacerbation (PESE), also referred to as post-exertional malaise (PEM), is defined as the worsening of symptoms that can follow minimal cognitive, physical, emotional, or social activity, or activity that could previously be tolerated. Symptoms typically worsen 12 to 72 hours after activity and can last for days or even weeks, sometimes leading to a relapse.

Reduced arm span · Frequent (79-30%)

Decreased length of the arm span (length from one end of an individual's arms measured at the fingertips to the other when raised parallel to the ground at shoulder height at a one-hundred eighty degree angle).

Abnormal patella morphology · Occasional (29-5%)

Abnormality of the patella (knee cap).

Abnormality of the ankles · Occasional (29-5%)

An anomaly of the joint that connects the foot with the leg.

Abnormality of the epiphyses of the feet · Occasional (29-5%)

Any abnormality of the epiphyses of the feet.

Abnormality of the knee · Occasional (29-5%)

An abnormality of the knee joint or surrounding structures.

Bilateral coxa valga · Occasional (29-5%)

The presence of bilateral coxa valga.

Coxa vara · Occasional (29-5%)

Coxa vara includes all forms of decrease of the femoral neck shaft angle (the angle between the neck and the shaft of the femur) to less than 120 degrees.

Fragmentation of the metacarpal epiphyses · Occasional (29-5%)

Fragmented appearance of the epiphyses of the metacarpals.

Genu valgum · Occasional (29-5%)

The legs angle inward, such that the knees are close together and the ankles far apart.

Other findings in the same source

From: Orphanet

Additional reported features include Genu varum (Occasional (29-5%)); Osteoarthritis (Occasional (29-5%)); Short stature (Occasional (29-5%)); Waddling gait (Occasional (29-5%)); Abnormality of radial epiphyses (Occasional (29-5%)); Abnormality of the epiphyses of the elbow (Occasional (29-5%)); Radially deviated wrists (Occasional (29-5%)); Ulnar deviated club hands (Occasional (29-5%)); Muscle weakness (Very rare (<4-1%)); Myopathy (Very rare (<4-1%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Adolescent; Childhood

Inheritance in the source

From: Orphanet

Autosomal dominant

Frequency and the population described

From: Orphanet

Reported case(s): 59.0; Worldwide. This is a published case count, not prevalence. Point prevalence: <1 / 1 000 000; Worldwide; Class only.

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 Multiple epiphyseal dysplasia due to collagen 9 anomaly 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 Multiple epiphyseal dysplasia due to collagen 9 anomaly. 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.