What are the types of Ehlers-Danlos syndromes?
(formerly types I & II)
Marked joint hypermobility, skin hyperextensibility (laxity), and fragility are characteristic of the classic type of Ehlers-Danlos syndrome. The smooth, velvety skin is fragile and tears or bruises easily with minor trauma. Joint dislocations and scoliosis are common. Joint instability can lead to sprains and strains. This classical type is inherited as an autosomal dominant genetic trait (directly passed on from one parent to child).
(formerly type III)
Joint hypermobility is the major manifestation of this form of Ehlers-Danlos syndrome. Any joint can be affected, and dislocations are frequent. This type is also inherited as an autosomal dominant genetic trait.
(formerly type IV, the arterial form)
In this form of Ehlers-Danlos syndrome, spontaneous rupture of arteries and bowel is a serious manifestation that can lead to death. Clubfoot can be present at birth. Skin laxity is of varying degrees. Veins can be very visible through the skin. It is primarily inherited as an autosomal dominant (directly passed on from one parent to child) genetic trait, but recessive (not seen in family members or only in one generation of members of the same family, meaning that an individual must inherit two copies of the mutation, one from each parent) trait inheritance has been described.
(formerly type VI)
Fragile globe of the eyes, significant skin and joint laxity, and severe curvature of the spine (scoliosis) are typical features. Its inheritance pattern is autosomal recessive.
(formerly type VIIB, arthrochalasis multiplex congenita)
Patients are short in height and severely affected by joint laxity and dislocations. Skin involvement is variable. Both utosomal dominant and recessive inheritance is possible. A skin biopsy can be used to diagnose this disorder.
(formerly type VIIC)
Patients have severely fragile skin that is soft and doughy with sagging and folding. This rare form of Ehlers-Danlos syndrome can be diagnosed with a skin biopsy.
Tenascin-X deficient type
Joint hypermobility, hyperelastic skin, and fragile tissue are seen. Patients with this type lack the multiple shrinking (atrophied) scars in the skin that are often seen in classic Ehlers-Danlos. It is inherited as an autosomal recessive genetic trait.
Other rare variant types have been reported in single families.