Note: All links within
content go to MayoClinic.com
Diseases and Conditions
Ehlers-Danlos syndrome
From MayoClinic.com
Special to CNN.com
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
Classical type (formerly types I and II)
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
Kyphoscoliosis type (formerly called type VI)
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
Arthrochalasia type (formerly called types VII A and B)
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
Dermatosparaxis type (formerly called type VII C)
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
Other types
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.
Severity of signs and symptoms vary widely. Some people with EDS may experience greater difficulty than others do. 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. Risk factors The biggest risk factor for Ehlers-Danlos syndrome is a family history of the disease. You can inherit subtypes of EDS in patterns of inheritance called autosomal dominant, autosomal recessive, and X-linked recessive patterns. Autosomal dominant inheritance
You receive your genes, the segments of DNA that hold the entire recipe for you as a person, from your parents. Genes occur in pairs. One half of each pair is inherited from your mother, the other half is from your father. Genes can be dominant or recessive. In a gene pair, the effects of the dominant gene take precedence over the effects of the recessive one. If the dominant gene is altered (mutated), that mutation will control the gene's expression, sometimes resulting in disease. Diseases that are caused by dominant gene mutations are called autosomal dominant disorders. The hypermobility and classical subtypes of EDS are autosomal dominant disorders. So is the periodontal form (type VIII). If you inherit a dominant gene mutation for one of these subtypes, you'll develop the signs and symptoms of that condition, usually apparent in childhood. There's also a 50 percent chance that you'll pass the gene on to each of your children. Autosomal recessive inheritance
Some mutations that cause Ehlers-Danlos syndrome occur in recessive genes — they're termed autosomal recessive disorders. The kyphoscoliosis, arthrochalasis and dermatosparaxis subtypes of EDS may occur as autosomal recessive disorders, although they sometimes may occur in autosomal dominant fashion. For a couple to have children with an autosomal recessive disorder, both parents must carry the associated recessive genetic mutation, even if they don't have the disorder themselves (silent mutation). In this case, they are only "carriers" of the disorder. The chances are one in four that such a couple will have a child that inherits both recessive genes and subsequently develops the disorder, one in two that the child will be a healthy, unaffected carrier and one in four that the child will neither carry the altered gene nor have the disease. If only one parent has the disorder — meaning he or she carries two mutated recessive genes — all children will inherit one copy of the altered gene, but probably will not develop the disorder. However, if it happens that the other parent is also a carrier of the same gene — which is unlikely since these are rare disorders — then each child would have a 50 percent chance of being affected. X-linked recessive inheritance
The cause of some of the rare EDS subtypes — types V and IX, now classified as "other" — is recessive genetic mutations found on the female sex (X) chromosome. These are called X-linked recessive disorders. These are more likely to develop in men because they only carry one X chromosome — the other male chromosome is a Y chromosome. Women may carry the defective recessive gene but generally don't develop the disorder because the other normal X chromosome — women carry two X chromosomes — takes over for the mutated one. If a mother is a carrier and the father is normal, their son has a 50 percent chance of inheriting the condition. A daughter has a 50 percent chance of being a carrier, like her mother. If the father is the one affected and the mother is normal, their daughters will be carriers but their sons won't be affected because they'll inherit only the Y chromosome from their father. When to seek medical advice If you or your child has signs or symptoms of Ehlers-Danlos syndrome, make an appointment to talk with your doctor. If you're concerned about a family history of EDS, you may wish to consult your doctor or a genetic counselor for help in assessing your risk or in planning a family. Screening and 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. Other tests your doctor may use to help with diagnosis include: - Genetic tests. There are a few tests that can detect certain collagen gene alterations through DNA analysis. These tests may help identify vascular and arthrochalasia types of EDS.
- 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.
- Prenatal diagnostic tests. Prenatal diagnostic tests may be available for certain types of EDS if the genetic mutation has been identified in a relative. Kyphoscoliosis type can be diagnosed through amniocentesis, a test that analyzes a sample of amniotic fluid, the fluid that surrounds the baby, for levels of enzyme activity. Vascular type EDS can be identified through genetic testing of amniotic fluid.
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
People with vascular type EDS may have more serious complications, including rupture of major blood vessels or organs, such as the intestines or uterus. These complications can be fatal. 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. 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.
- 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.
Coping skills Coping with a lifelong illness is rarely easy. Depending on the severity of your symptoms, you may face challenges at home, work and in your relationships with others. Parents of children with EDS have sometimes encountered suspicions of child abuse because of frequent bruises and cuts. Here are some suggestions that may help you cope with the challenges of EDS: - Increase your knowledge. Being knowledgeable of EDS is an important step in taking control of your condition. Find a doctor who's experienced in the management of EDS and learn as much as you can about the type of EDS you have.
- Tell others. Explain your condition to family members, friends and to your employer. Ask your employer if he or she can make any accommodations that you feel will make you a more productive worker. It's up to you how much information you divulge to your co-workers. You may want to prepare an appropriate response for people who ask questions.
- Build support. Having a strong support network can help. Build up relationships with family and friends who are positive and caring. It may also help to talk to an unrelated third party, such as a medical social worker, counselor or clergy member. Some people find help by joining a support group for people with EDS or people with chronic illnesses. The Ehlers-Danlos Foundation's Web site has information on local and regional support groups.
Helping your child cope
Family members can play critical roles in helping a child cope with EDS. As a parent, you may want to try the following: - Maintain normalcy. Treat your child, as much as possible, like other normal children. Ask others — grandparents, aunts, uncles — to do the same.
- Be open. Allow your child to express his or her feelings about having EDS, even if it means being angry at times. Also, make sure your child's teachers and other caregivers know about your child's condition. Review with them appropriate caregiving skills, particularly in situations such as a fall or injury.
- Promote activity. Encourage your child to participate in physical activities, keeping in mind the recommendations of your child's doctor and physical therapist.
- Find the best routine. Work with your child's teachers and school administrators to make any necessary modifications in his or her schedule or responsibilities. These modifications may include giving your child extra time to move from class to class, providing him or her with an extra set of textbooks so that these books won't need to be carried home, and making arrangements for assignments to be sent home when your child misses school because of his or her condition.
Most people with EDS are able to live a productive and fulfilling life, even with the limitations imposed by having EDS.
Slide show: How genetic disorders are passed from parents to children
|
