About Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) is a group of inherited disorders that affect your connective tissues — primarily your skin, joints and blood vessel walls. With EDS, genetic mutations disrupt the production of collagen, a chief component of connective tissue.

Ehlers-Danlos syndrome is uncommon and occurs in six major types. All types affect your joints, and most also affect your skin. Some of the more prominent symptoms of Ehlers-Danlos syndrome include flexible joints that extend beyond the normal range of movement, and skin that’s especially stretchy or fragile.

You may have normal yet very flexible joints, or “double joints.” This isn’t the same as Ehlers-Danlos syndrome.

Treatment of Ehlers-Danlos syndrome usually focuses on managing the signs and symptoms of the particular type that you have.

Causes

The subtypes of Ehlers-Danlos syndrome are caused by a variety of genetic alterations (mutations) that disrupt the normal production of collagen. Collagen is a fibrous protein that gives strength and elasticity to connective tissues — skin, tendons, ligaments, cartilage, and organ and blood vessel walls.

These genetic mutations, which are passed on from parent to child, alter normal enzyme activity, leaving connective tissues weak and unstable.

Variety of inheritance patterns
Most EDS types are passed along in an inheritance pattern called autosomal dominant. This means you only need one copy of the disease-causing mutation, inherited from either parent, to develop signs and symptoms of the disease. If you inherit the mutation, there’s a 50 percent chance that you’ll pass the gene on to each of your children.

Two EDS types — kyphoscoliosis and dermatosparaxis — are passed along in an inheritance patter called autosomal recessive. This means you need two copies of the mutated gene to develop the disease. If you inherit only one copy, you’re considered a “carrier” of the disorder, but you likely won’t develop signs or symptoms.

Symptoms

The severity of signs and symptoms of Ehlers-Danlos syndrome can vary widely. Some people may experience greater difficulty than others do. In general, signs and symptoms include:

  • Skin that’s especially stretchy or fragile
  • Hernias
  • Abnormal wound healing, scars that stretch over time
  • Flexible joints that extend beyond the normal range of movement
  • Dislocations of your shoulder, knee, fingers, hip, wrist and collarbone
  • Muscle weakness
  • Delayed motor development
  • Easy bruising
  • Heart problems, such as mitral valve prolapse, aortic root dilatation and spontaneous rupture of large arteries
  • Family history of ruptured uterus, colon or brain aneurysm

Ehlers-Danlos syndrome is divided into six major groups, based on specific diagnostic criteria:

Hypermobility type (formerly type III)
This is the most common form. It may affect as many as one in 10,000 to 15,000 people. Signs and symptoms include:

  • Loose, unstable joints
  • Soft, velvety skin
  • Chronic degenerative joint disease
  • Advanced premature osteoarthritis with chronic pain
  • Heart valve problems (mitral valve prolapse)

Classical type (formerly types I and II)
This type probably affects about one in 20,000 to 40,000 people. Signs and symptoms include:

  • Loose joints, which are prone to dislocation and may delay the development of large-motor skills, especially when a child starts to walk
  • Highly elastic, velvety skin
  • Fragile skin that bruises or tears easily
  • Slow and poor wound healing leading to wide scarring
  • Noncancerous fibrous growths on pressure areas, such as elbows and knees; fatty growths on the shins and forearms
  • Hernias
  • Heart valve problems (mitral valve prolapse)

Vascular type (formerly type IV)
This is one of the most serious forms of EDS. It affects an estimated one in 250,000 people. Signs and symptoms include:

  • Fragile blood vessels and organs that are prone to tearing (rupture), causing complications such as a ruptured or dissected artery or an aneurysm, ruptured intestines or a ruptured uterus during pregnancy
  • Thin, fragile skin that bruises easily
  • Veins visible beneath the skin
  • Characteristic facial appearance, including protruding eyes, thin nose and lips, sunken cheeks and small chin
  • Loose joints, usually limited to the fingers and toes

Kyphoscoliosis type
This uncommon form has few cases reported worldwide. Signs and symptoms include:

  • Progressive curvature of the spine (kyphoscoliosis) with respiratory problems, if severe
  • Fragile eyes that are easily damaged or ruptured
  • Muscle weakness
  • Increased risk of rupture of medium-sized arteries

Arthrochalasis type
Arthrochalasis is rare. Only about 30 cases have been reported worldwide. Signs and symptoms include:

  • Very loose joints and dislocation of both hips, present at birth
  • Stretchy, fragile skin that’s prone to bruising and scarring
  • Early-onset arthritis
  • Increased risk of bone loss and fracture

Dermatosparaxis type
This form is also rare, with only about a dozen cases reported worldwide. Signs and symptoms include:

  • Extremely fragile and sagging skin
  • Loose joints, which may delay development of motor skills in children
  • Short stature
  • Delayed closure of the fontanels, the soft areas at the top of a baby’s head
  • Characteristic facial appearance with swollen eyelids and a bluish tinge to the whites of the eyes
  • Umbilical hernia
  • Short fingers

Other types
There are other rare types of EDS. Some of these are so rare that they’ve only been described in a few families. In addition, the relationship of some of these types to the syndrome as a whole isn’t well-defined.

Diagnosis

To diagnose Ehlers-Danlos syndrome, your doctor will likely begin with a complete physical examination and a careful recording of your medical and family histories. Extremely loose joints, fragile skin and a family history of EDS may lead to a diagnosis. Your doctor may also order the following tests:

  • Genetic tests. DNA testing is available for classical type EDS, vascular type EDS, kyphoscoliosis type EDS and arthrochalasis type EDS. Prenatal DNA testing and preimplantation genetic diagnosis, a method that tests embryos obtained by in vitro fertilization, may be available for families in which the disease-causing mutation has been identified.
  • Urine test. A urine test is available to help identify kyphoscoliosis type. The test measures the levels of an enzyme produced by the gene associated with kyphoscoliosis type. Abnormal levels of the enzyme typically indicate this form of EDS.
  • Skin biopsy. In this test, a small sample of your skin is removed and examined under a microscope. Such a test may reveal abnormalities in the skin’s collagen fibers. Vascular type EDS can be diagnosed by analyzing collagen produced by skin cells.
  • Heart ultrasound. To check for mitral valve prolapse, a heart condition that can occur with the classical and hypermobility EDS subtypes, your doctor may recommend a heart ultrasound (echocardiogram). A heart ultrasound provides real-time images of your heart in motion. It can help identify abnormalities in the heart muscle and valves, and find any fluid that may surround the heart.

Treatment

There’s no way to reverse the genetic alterations that cause Ehlers-Danlos syndrome. Treatment focuses primarily on managing individual signs and symptoms and preventing further complications. Much of this consists of self-care strategies to protect your joints and prevent excessive bruising and injuries. Your health care team may include specialists from a variety of different fields, including medical genetics, surgery, pediatrics, orthopedics, cardiology and ophthalmology, to name a few.

Surgical considerations
If you’re to undergo surgery, make sure your surgeon knows you have Ehlers-Danlos syndrome. Your surgeon may use adhesive tape or medical glue rather than stitches to close up incisions, because stitches may tear out of fragile skin. Surgery is sometimes required to repair joints damaged by repeated dislocations. Elective surgery isn’t recommended.

Managing pain
If you have chronic joint pain, talk to your doctor about ways to help manage the pain. This might include use of pain relievers or physical therapy or both. A physical therapist can help you develop an exercise program to strengthen your muscles, which in turn will help stabilize your joints. In general, people with EDS need to avoid activities that put pressure on locked joints, such as weightlifting. Your therapist or doctor can prescribe appropriate exercises for you.

Although a few reports indicate that vitamin C may help reduce the severity of kyphoscoliosis symptoms, this hasn’t been established.

Self-care

Preventing injuries and protecting your skin and joints are a big part of self-care for Ehlers-Danlos syndrome. Here are a few suggestions:

  • Avoid injury. Avoid contact sports and other activities that increase your risk of injury.
  • Use protective gear. If you have a toddler or young child with severe EDS, you might consider dressing him or her with protective clothing, guards or padding to protect from tumbles and falls, especially while he or she is learning to walk and move around.
  • Reduce the clutter. To prevent falls and injuries at home, keep walkways and doorways clear of clutter. Avoid loose rugs and electric cords, which can increase your risk of tripping and falling.
  • Use assistive devices. A number of common devices can help decrease stress on your joints, such as jar openers, utensils with wide handles, and long-handled combs or bath sponges.
  • Wear sunscreen. Regular use of sunscreen when you’re exposed to the sun may help reduce premature aging of your skin.

Prevention

If you have a personal or family history of Ehlers-Danlos syndrome and you’re thinking about starting a family, you may benefit from talking to a genetic counselor — a health care professional trained to assess the risk of inherited disorders. Genetic counseling can help you understand the inheritance pattern of the type of EDS that affects you and the risks it poses for your children.