Ehlers-Danlos Syndrome

Ehlers-Danlos syndromes are a group of disorders that share common features including easy bruising, joint hypermobility (loose joints), skin that stretches easily (skin hyperelasticity or laxity), and weakness of tissues.

The Ehlers-Danlos syndromes are inherited in the genes that are passed from parents to offspring. They are categorized according to the form of genetic transmission into different types with many features differing between patients in any given type. Fragile skin and loose joints are often a result of abnormal genes that produce abnormal proteins that confer an inherited frailty of collagen (the normal protein "glue" of our tissues).

In 2001, researchers discovered a new form of Ehlers-Danlos syndrome that is caused by an inherited abnormality in a protein other than collagen that also normally plays a role in binding together the cells of our tissues (including the skin, tendons, muscle, and blood vessels). Abnormalities in this protein, called tenascin, also lead to a form of Ehlers-Danlos syndrome. Researchers suspect that tenascin could play a role in regulating the normal distribution of collagen in the connective tissues of the body.

Classical type
(formerly types I & II)

• Marked joint hypermobility, skin hyperextensibility (laxity), and fragility are characteristics 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).

Hypermobility type
(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.

Vascular type
(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.

Kyphoscoliosis type
(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.

Arthrochalsia type
(formerly type VIIB, arthrochalasis multiplex congenita)

• Patients are short in height and severely affected by joint laxity and dislocations.
• Skin involvement is variable.
• Both autosomal dominant and recessive inheritance is possible.
• A skin biopsy can be used to diagnose this disorder.

Dermatosparaxis type
(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.

Ehlers-Danlos Syndrome can be triggered by a number of factors, such as:

• Joint injury or overuse
• Emotional stress
• Changes in temperature or weather
• Certain medications or foods
• Fatigue or poor sleep
• Infections or illness

• Symptoms of Ehlers-Danlos syndromes include:
  • Loose skin that stretches away from the body easily and excessively.
  • The skin can appear saggy and soft and may tear easily and be fragile.
• Signs of Ehlers-Danlos syndromes include:
  • Easy bruising without significant trauma and joints that can move beyond the normal range of motion.
  • Joint hypermobility in Ehlers-Danlos syndromes can lead to multiple joint dislocations.

The diagnosis of Ehlers-Danlos syndrome is based on the clinical findings of the patient and the family history. For some types of Ehlers-Danlos syndrome, a skin biopsy to determine the chemical makeup of the connective tissue can help to suggest the diagnosis.

Ehlers-Danlos syndromes are treated according to the particular manifestations present in a given individual.

• Skin protection (from injury or trauma and sun, etc.) is critical.
• Wounds must be tended to with great care and infections treated and prevented.
• Suturing can be difficult as the skin can be extremely fragile.

Joint injury must be avoided for a person with Ehlers-Danlos syndrome. 

• Occasionally, bracing may be necessary to maintain joint stability.
• Exercises that strengthen the muscles that support the joints can help to minimize joint injury. Contact sports and activities involving joint impact should be avoided.

The life expectancy for Ehlers-Danlos Syndrome varies depending on the type and severity of the condition and the person's overall health and access to medical care. Generally, people with milder forms of EDS have a normal life expectancy. In contrast, those with severe forms of EDS have a reduced life expectancy due to an increased risk of life-threatening complications.