Merck Manual

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Ehlers-Danlos Syndrome


Frank Pessler

, MD, PhD, Braunschweig, Germany

Last full review/revision May 2019| Content last modified Jun 2019
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Ehlers-Danlos syndrome is a rare hereditary disorder of connective tissue that results in unusually flexible joints, very elastic skin, and fragile tissues.

  • This syndrome is caused by a defect in one of the genes that control the production of connective tissue.

  • Typical symptoms include flexible joints, a humpback, flat feet, and elastic skin.

  • The diagnosis is based on symptoms and results of a physical examination.

  • Most people with this syndrome have a normal life span.

  • There is no cure for Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome is caused by an abnormality in one of the genes that controls the production of connective tissue. Connective tissue is the tough, often fibrous tissue that binds the body's structures together and provides support and elasticity.

There are 6 major types (with widely varying severity) of Ehlers-Danlos syndrome involving different genes and causing slightly different changes. The result is abnormally fragile connective tissue, which causes problems in joints and bones and may weaken internal organs.


Children with Ehlers-Danlos syndrome usually have very flexible joints. Some develop small, hard, round lumps under the skin, a chest deformity, a humpback with an abnormal curve of the spine (kyphoscoliosis), or a clubfoot. Most adults have flat feet. The skin can be stretched up to several inches but returns to its normal position when released.

Complications of Ehlers-Danlos syndrome

Ehlers-Danlos syndrome may alter the body’s response to injuries. Minor injuries may result in wide gaping wounds. Although these wounds usually do not bleed excessively, they leave wide scars. Sprains and dislocations develop frequently.

In a small number of children with Ehlers-Danlos syndrome, the blood does not clot normally, so bleeding from minor wounds may be difficult to stop.

The intestines can bulge through the abdominal wall (called a hernia), and abnormal outpouchings (diverticula) can develop in the intestine. Rarely, a fragile intestine bleeds or ruptures (perforates—see Perforation of the Digestive Tract). Sometimes weak tissue in a heart valve causes the valve to leak.

If a pregnant woman has Ehlers-Danlos syndrome, delivery may be premature. The mother's fragile tissues may make an episiotomy or cesarean delivery difficult. If the fetus has Ehlers-Danlos syndrome, the amniotic sac may rupture early (premature rupture of membranes). A mother or baby who has Ehlers-Danlos syndrome can bleed excessively before, during, and after delivery.


  • A doctor's evaluation

  • Genetic testing

  • Skin biopsy

  • Imaging tests

A doctor bases the diagnosis of Ehlers-Danlos syndrome on the symptoms and results of a physical examination. To confirm the diagnosis, genetic tests are usually done.

The doctor can try to determine some of the types of Ehlers-Danlos syndrome by taking a sample of skin to examine under a microscope (biopsy).

Other tests are done to check for conditions that are associated with complications. For example, echocardiography and other imaging tests are usually done to detect problems with the heart or blood vessels.


Despite the many and varied complications people with Ehlers-Danlos syndrome may have, their life span is usually normal. However, in a few people with one type of Ehlers-Danlos syndrome, complications (usually bleeding) are fatal.


  • Injury prevention

There is no way to cure Ehlers-Danlos syndrome or correct the abnormalities in the connective tissue. Injuries can be treated, but it may be difficult for a doctor to stitch cuts because stitches tend to tear out of the fragile tissue. Usually, using an adhesive tape or medical skin glue closes cuts more easily and leaves less scarring.

Special precautions should be taken to prevent injuries. For example, children with severe forms of Ehlers-Danlos syndrome can wear protective clothing and padding.

Surgery requires special techniques that minimize injury and ensure that a large supply of blood is available for transfusion. An obstetrician (a doctor who specializes in childbirth and in caring for and treating women who are giving birth) must supervise pregnancy and delivery. Genetic counseling for family members is suggested.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
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