Dyggve-Melchior-Clausen disease

What it is

From: Orphanet

A rare, genetic primary bone dysplasia of the spondylo-epi-metaphyseal dysplasia (SEMD) group characterized by progressive short-trunked dwarfism, protruding sternum, microcephaly, intellectual disability and pathognomonic radiological findings (generalized platyspondyly with double-humped end plates, irregularly ossified femoral heads, a hypoplastic odontoid, and a lace-like appearance of iliac crests)

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.

Disproportionate short-trunk short stature · Very frequent (99-80%)

A type of disproportionate short stature characterized by a short trunk but a average-sized limbs.

Failure to thrive · Very frequent (99-80%)

Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.

Intellectual disability · Very frequent (99-80%)

The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence.

Spondyloepimetaphyseal dysplasia · Very frequent (99-80%)

Abnormality of the femoral head · Frequent (79-30%)

An abnormality of the femoral head.

Abnormality of the hip bone · Frequent (79-30%)

An abnormality of the hip bone.

Abnormality of the vertebral column · Frequent (79-30%)

Any abnormality of the vertebral column.

Abnormality of the vertebral endplates · Frequent (79-30%)

Any abnormality of the vertebral end plates, which are the top and bottom portions of the vertebral bodies that interface with the vertebral disks.

Beaking of vertebral bodies · Frequent (79-30%)

Anterior tongue-like protrusions of the vertebral bodies.

Broad femoral neck · Frequent (79-30%)

An abnormally wide femoral neck (which is the process of bone, connecting the femoral head with the femoral shaft).

Broad ribs · Frequent (79-30%)

Increased width of ribs

Coarse facial features · Frequent (79-30%)

Absence of fine and sharp appearance of brows, nose, lips, mouth, and chin, usually because of rounded and heavy features or thickened skin with or without thickening of subcutaneous and bony tissues.

Gait disturbance · Frequent (79-30%)

The term gait disturbance can refer to any disruption of the ability to walk.

Horizontal inferior border of scapula · Frequent (79-30%)

A morphological abnormality of the scapula in which there is a flat (horizontal) inferior edge of the scapula. The entire scapula is said to resemble a square, leading to the designation sqaring of the scapula (in Figure 1 of PMID:24706940 the scapulae have a roughly rectangular shape).

Other findings in the same source

From: Orphanet

Additional reported features include Hypoplasia of the capital femoral epiphysis (Frequent (79-30%)); Hypoplastic acetabulae (Frequent (79-30%)); Hypoplastic ilia (Frequent (79-30%)); Iliac crest serration (Frequent (79-30%)); Intellectual disability, severe (Frequent (79-30%)); Limb muscle weakness (Frequent (79-30%)); Metaphyseal dysplasia (Frequent (79-30%)); Microcephaly (Frequent (79-30%)); Motor delay (Frequent (79-30%)); Pectus carinatum (Frequent (79-30%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Infancy

Inheritance in the source

From: Orphanet

Autosomal recessive

Frequency and the population described

From: Orphanet

Reported case(s): 100.0; 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 recessive pattern usually involves disease-causing changes in both copies of a gene. Parents may each carry one altered copy without having the condition themselves. A genetic counsellor can explain carrier testing and reproductive implications using the actual laboratory findings, rather than the condition name alone.

Which doctor should you see?

The suggested department for discussing Dyggve-Melchior-Clausen 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 Dyggve-Melchior-Clausen 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.