Spondylometaphyseal dysplasia, Sedaghatian type

What it is

From: Orphanet

A rare spondylodysplastic dysplasia characterized by severe neonatal hypotonia, spondylometaphyseal dysplasia, cardiac arrhythmia, and central nervous system anomalies leading to death in the first days of life due to cardiorespiratory failure. Skeletal anomalies include irregular appearance of the iliac crest and bone, abnormal long bones of the extremities (including shortening, widening and cupping), and increased intervertebral disc space. Visceral anomalies include subendocardial myocarditis, myocardial necrosis, adrenal and pulmonary hemorrhage. Cranial magnetic resonance imaging reveals intracranial abnormalities such as simplified gyral pattern, hypogenesis of the corpus callosum, and cerebellar hypoplasia.

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.

Abnormal rib morphology · Very frequent (99-80%)

An anomaly of the rib.

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

Any abnormality of the scapula, also known as the shoulder blade.

Arrhythmia · Very frequent (99-80%)

Any cardiac rhythm other than the normal sinus rhythm. Such a rhythm may be either of sinus or ectopic origin and either regular or irregular. An arrhythmia may be due to a disturbance in impulse formation or conduction or both.

Atrioventricular block · Very frequent (99-80%)

Delayed or lack of conduction of atrial depolarizations through the atrioventricular node to the ventricles.

Delayed skeletal maturation · Very frequent (99-80%)

A decreased rate of skeletal maturation. Delayed skeletal maturation can be diagnosed on the basis of an estimation of the bone age from radiographs of specific bones in the human body.

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

A kind of short stature in which different regions of the body are shortened to differing extents.

Iliac crest serration · Very frequent (99-80%)

Irregularities of the iliac crest that produce the appearance of a lace border around it.

Long fibula · Very frequent (99-80%)

Disproportionately long fibulae.

Metaphyseal chondrodysplasia · Very frequent (99-80%)

An abnormality of skeletal development characterized by a disturbance of the metaphysis and its histological structure with relatively normal epiphyses and vertebrae.

Platyspondyly · Very frequent (99-80%)

A flattened vertebral body shape with reduced distance between the vertebral endplates.

Rhizomelic arm shortening · Very frequent (99-80%)

Disproportionate shortening of the proximal segment of the arm (i.e. the humerus).

Short metacarpal · Very frequent (99-80%)

Diminished length of one or more metacarpal bones in relation to the others of the same hand or to the contralateral metacarpal.

Short palm · Very frequent (99-80%)

Short palm.

Cardiorespiratory arrest · Very frequent (99-80%)

Other findings in the same source

From: Orphanet

Additional reported features include Spondylometaphyseal dysplasia (Very frequent (99-80%)); Cerebellar hypoplasia (Frequent (79-30%)); Generalized hypotonia (Frequent (79-30%)); Narrow chest (Frequent (79-30%)); Turricephaly (Frequent (79-30%)); Respiratory insufficiency (Frequent (79-30%)); Accelerated skeletal maturation (Occasional (29-5%)); Agenesis of corpus callosum (Occasional (29-5%)); Cone-shaped epiphysis (Occasional (29-5%)); Myocarditis (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Antenatal; Neonatal

Inheritance in the source

From: Orphanet

Autosomal recessive

Frequency and the population described

From: Orphanet

Reported case(s): 9.0; 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 Spondylometaphyseal dysplasia, Sedaghatian type 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 Spondylometaphyseal dysplasia, Sedaghatian type. 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.