Ehlers-Danlos syndrome
Introduction
Ehlers-Danlos syndrome (EDS) refers to a group of inherited disorders that affect your connective tissues — primarily your skin, joints and blood vessel walls. The cause is genetic defects that disrupt the production of collagen, a chief component of connective tissue.
There are six major types of Ehlers-Danlos syndrome. These types are categorized based on signs and symptoms. All types affect your joints, and most also affect your skin. Some of the more prominent signs and symptoms include joints that extend beyond the normal range of movement, and skin that's especially stretchy or fragile.
Ehlers-Danlos syndrome is relatively uncommon. The frequency of its occurrence depends on the type of Ehlers-Danlos syndrome. If your doctor suspects Ehlers-Danlos syndrome, he or she may refer you to a geneticist to determine the specific type.
There's no cure for Ehlers-Danlos syndrome. Treatment usually focuses on managing the signs and symptoms of the particular type.
Signs and Symptoms
In the past, experts divided Ehlers-Danlos syndrome into 11 subtypes — I through XI. In 1997, in an attempt to simplify these classifications, scientists reorganized the subtypes according to signs and symptoms, arranging them into six different groups:
Hypermobility type (formerly type III)
This is the most common form of EDS. It may affect as many as one in 10,000 to 15,000 people. Signs and symptoms include:
- Loose, unstable joints
- Chronic joint pain
This type probably affects fewer than one in 20,000 to 40,000 people. Signs and symptoms include:
- Highly elastic, velvety skin
- Fragile skin that bruises or tears easily
- Slow and poor wound healing leading to scarring
- Noncancerous fibrous growths on pressure areas, such as elbows and knees; fatty growths on the shins and forearms
- Loose joints, which are prone to dislocation and may delay the development of large-motor skills
Vascular type (formerly type IV)
This is one of the most serious forms of EDS. It affects an estimated one in 100,000 to 200,000 people. Signs and symptoms include:
- Fragile blood vessels and organs that are prone to tearing (rupture)
- Thin, fragile skin that bruises easily
- Veins visible beneath the skin
- Distinctive facial features, including protruding eyes, thin nose and lips, sunken cheeks and small chin
- Loose joints, usually limited to the fingers and toes
This is an uncommon form. Fewer than 60 cases have been reported worldwide. Signs and symptoms include:
- Progressive curvature of the spine (scoliosis)
- Fragile eyes that are easily damaged
- Severe, progressive muscle weakness
Arthrochalasis is rare. Only about 30 cases have been reported worldwide. Signs and symptoms include:
- Very loose joints and dislocations, involving both hips, which may delay the development of large-motor skills
- Stretchy, fragile skin that's prone to bruising
- Early-onset arthritis
- Increased risk of bone loss and fracture
This form is also very rare. Only about 10 cases have been reported worldwide. Signs and symptoms include:
- Extremely fragile and sagging skin
- Loose joints, which may delay development of large-motor skills in children
The remaining subtypes — types V, VIII, IX, X and XI — are classified as other. These are rare, and some aren't well-defined. Some characteristics of these types:
- Type V has characteristically fragile skin, although bruising and loose joints are uncommon.
- Type VIII involves teeth and gums as well as skin and joints (periodontal form).
- Type IX may cause chronic diarrhea and lightheadedness due to low blood pressure, in addition to other signs and symptoms.
- Types X and XI, characterized by loose joints, are very similar and have sometimes been considered one type rather than two.
- Type X may lead to problems with blood clotting.
Some people have normal yet very flexible joints, or "double joints." This isn't the same as Ehlers-Danlos syndrome.
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's one of the major components of connective tissue. These genetic mutations are passed on from parent to child.
Collagen fibers give connective tissues — skin, tendons, ligaments, cartilage, and organ and blood vessel walls — strength and elasticity. People with Ehlers-Danlos syndrome lack appropriate collagen synthesis, leaving their connective tissues weak and unstable.
Complications
Most people with Ehlers-Danlos syndrome live a relatively normal life, although there may be restrictions to physical activity. EDS doesn't affect your intelligence.
Signs and symptoms of EDS vary widely in severity, ranging from mild to severe. Complications often depend on your individual situation. Common complications tend to include:
- Prominent scarring
- Difficulty with surgical wounds — stitches may tear out, or healing may be incomplete
- Chronic joint pain
- Early-onset arthritis
- Premature aging with sun exposure
Having kyphoscoliosis type places you at increased risk of eye problems. You may need to be monitored by an eye specialist, ideally one who has experience with EDS complications.
Some people with EDS may develop Osteoporosis. Osteoporosis is generally treated with prescription medications to increase bone density. Specific physical therapy exercises may help, too.
Pregnancy and EDS
If you're pregnant and have EDS, there's a risk of premature delivery. If your baby has EDS, there's a risk of premature rupture of the membranes surrounding it. In either case, there's also a risk of excessive bleeding. Your doctor will probably suggest monitoring your pregnancy closely for any signs of complications.
Treatment
There's no way to reverse the genetic alterations that cause EDS. Treatment focuses primarily on managing individual signs and symptoms. Much of this consists of self-care strategies to protect your joints and prevent excessive bruising and injuries.
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. Talk to your doctor if you're thinking about taking a vitamin C supplement.
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.
Informations obtained from National Institute of Health.