Spondylometaphyseal dysplasia Sedaghatian type

Alternate names

Lethal metaphyseal dysplasia

Definition

Spondylometaphyseal dysplasia (SEMD), Sedaghatian type is a neonatal lethal form of spondylometaphyseal dysplasia characterized by severe metaphyseal chondrodysplasia, mild rhizomelic shortness of the upper limbs, and mild platyspondyly.

Epidemiology

Nine cases have been reported so far in patients of Iranian, Yemeni and Caucasian origin.

Cause

Cause is unknown

Inheritance

Autosomal recessive inheritance, a 25% chance

Autosomal recessive inheritance has been suggested.

Signs and symptoms

• A lacy appearance of the iliac crests, long fibulae, abnormal tarsal bones, cardiac arrhythmia, and intracranial anomalies have been described.
• Intrauterine growth is normal. The majority of patients die in the first days of life with symptoms of cardiorespiratory insufficiency.
• Subacute myocarditis, cortical necrosis of kidneys, adrenal and pulmonary hemorrhage, absence of the corpus callosum and marked frontotemporal pachygyria have been found at autopsy.

Clinical presentation

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed.

80%-99% of people have these symptoms

• Abnormal scapula morphology(Abnormality of the shoulder blade)
• Abnormality of the ribs(Rib abnormalities)
• Arrhythmia(Abnormal heart rate)
• Atrioventricular block(Interruption of electrical communication between upper and lower chambers of heart)
• Cardiorespiratory arrest
• Delayed skeletal maturation(Delayed bone maturation)
• Iliac crest serration
• Long fibula(Long calf bone)
• Metaphyseal chondrodysplasia
• Platyspondyly(Flattened vertebrae)
• Rhizomelic arm shortening
• Short metacarpal(Shortened long bone of hand)
• Short palm
• Spondylometaphyseal dysplasia

30%-79% of people have these symptoms

• Cerebellar [[hypoplasia](Small cerebellum)
• Generalized hypotonia(Decreased muscle tone)
• Narrow chest(Low chest circumference)
• [[Turricephaly](Tall shaped skull)

5%-29% of people have these symptoms

• Accelerated skeletal maturation(Advanced bone age)
• Agenesis of corpus callosum
• Cone-shaped epiphysis(Cone-shaped end part of bone)
• Myocarditis(Inflammation of heart muscle)
• Pachygyria(Fewer and broader ridges in brain)

NIH genetic and rare disease info

• NIH info on Spondylometaphyseal dysplasia Sedaghatian type

Spondylometaphyseal dysplasia Sedaghatian type is a rare disease.

Resources

Frequently asked questions

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