Ehlers-Danlos syndrome

The Ehlers Danlos syndrome comprises a heterogenous group of collagen disorders (hereditary connective tissue disease).

Epidemiology

There is a recognised male predominance.

Clinical presentation

Clinically manifests by skin hyperelasticity and fragility, joint hyperimmobility and blood vessel fragility with bleeding diathesis ¹.

There is poor tissue healing with delayed healing with tissue paper like scarring ¹.

Sub-types

There are at least ten sub-types with variable inheritance patterns. The majority are autosomal dominant.

• types I,II and III are autosomal dominant with a unknown biochemical origin.
• type IV is autosomal dominant and involves the arteries, GI tract, uterus and skin. COL3A1 mutation result in type III collagen production.
• type VI is recessively inherited. It results from mutation in the gene that encodes lysl hydroxylase
• type VII is autosomal dominant . It results from COL1A1 and COL1A2 mutation that result in defective conversion of procollagen to collagen.
• types V, VIII, IX and X are very rare and their features have not been fully described ¹

Radiographic features

These are best discussed according to system.

Soft tissue findings include

• multiple ovoid calcifications (< 1cm ) in subcutaneous tissue
• ectopic ossification ²

Skeletal findings include

• haemarthrosis ( esp. knees)
• recurrent dislocation-including spontaneous dislocation of TMJ ³
• precocious osteoarthritis
• kyphoscoliosis
• spondylolisthesis

Chest / thoracic findings include

• diaphragmatic hernia
• emphysema
• fragile blood vessels
• arterial aneurysm formation
• increased occurence of arterial dissection : aortography contraindicated ²

Gastrointestinal findings include

• ectasiae of gastrointestinal tract