Ehlers-Danlos syndrome

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

Epidemiology

There is a recognized male predominance.

Clinical presentation

Ehlers-Danlos syndrome clinically manifests with

• skin hyperelasticity and fragility
• joint hypermobility
• blood vessel fragility with bleeding diathesis ¹
• poor tissue healing with delayed healing with tissue paper-like scarring ¹

Subtypes

There are at least ten subtypes with variable inheritance patterns. The majority are autosomal dominant:

• types I, II and III are autosomal dominant with an unknown biochemical origin.
• type IV (also called vascular Ehlers-Danlos syndrome ⁴) 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 a mutation in the gene that encodes lysyl hydroxylase
• type VII is autosomal dominant. It results from COL1A1 and COL1A2 mutation that results 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

The imaging findings of Ehlers-Danlos syndrome are best discussed according to system.

Soft tissue

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

Skeletal

• hemarthrosis (especially knees)
• recurrent dislocation: including spontaneous dislocation of the temporomandibular joint ³
• precocious osteoarthritis
• kyphoscoliosis
• spondylolisthesis
• arachnodactyly

Vascular

• fragile blood vessels
• arterial aneurysm formation
• increased occurrence of arterial dissection: aortography contraindicated ²
• dolichoectasia

Thoracic

• diaphragmatic hernia
• emphysema

Gastrointestinal

• ectasiae of the gastrointestinal tract