Vascular Ehlers-Danlos Syndrome
Ehlers-Danlos syndrome type IV, also known as the vascular type of Ehlers-Danlos syndrome (EDS), is an inherited connective tissue disorder defined by characteristic facial features (acrogeria) in most patients, translucent skin with highly visible subcutaneous vessels on the trunk and lower back, easy bruising, and severe arterial, digestive and uterine complications, which are rarely, if at all, observed in the other forms of EDS.
The estimated prevalence of forms of EDS varies between 1/10,000 and 1/25,000, with EDS type IV representing approximately 5 to 10% of cases.
The vascular complications may affect all anatomical areas, with a preference for arteries of large and medium diameter. Dissections of the vertebral arteries and the carotids in their extra- and intra-cranial segments (carotid-cavernous fistulae) are typical. There is a high risk of recurrent colonic perforations. Pregnancy increases the likelihood of a uterine or vascular rupture.
EDS type IV is caused by mutations in the COL3A1 gene coding for type III procollagen.
Diagnosis is based on clinical signs, non-invasive imaging, and the identification of a mutation of the COL3A1 gene.
In childhood, coagulation disorders and Silverman's syndrome are the main differential diagnoses; in adulthood, the differential diagnosis includes other Ehlers-Danlos syndromes, Marfan syndrome and Loeys-Dietz syndrome (see these terms).
Prenatal diagnosis can be considered in families where the mutation is known. Choriocentesis or amniocentesis, however, are associated with an elevated risk for pregnant women with this disease.
EDS type IV is inherited as an autosomal dominant trait.
Management and treatment
In the absence of a specific treatment for EDS type IV, medical intervention should be focused on symptomatic treatment and prophylactic measures. Arterial, digestive or uterine complications require immediate hospitalisation and observation in an intensive care unit. Invasive imaging techniques are contraindicated. A conservative approach is usually recommended when caring for vascular complications in a patient suffering from EDS type IV. Surgery may, however, be required urgently to treat potentially fatal complications.