Ehlers-Danlos syndromes (EDS) are a group of inherited connective tissue disorders caused by abnormalities in the structure, production, and/or processing of collagen.
- The signs and symptoms of EDS vary by type and range from mildly loose joints to life-threatening complications.
- Features shared by many types include joint hypermobility and soft, velvety skin that is highly elastic (stretchy) and bruises easily.
- Mutations in a variety of genes may lead to EDS; however, the underlying genetic cause in some families is unknown.
- Depending on the subtype, EDS may be inherited in an autosomal dominant or an autosomal recessive manner.
- There is no specific cure for EDS.
- The treatment and management is focused on preventing serious complications and relieving associated signs and symptoms.
ED syndrome; EDS; Ehlers Danlos syndrome
Arthrochalasia Ehlers-Danlos syndrome; Brittle cornea syndrome; Cardiac-Valvular Ehlers-Danlos syndrome The new classification, from 2017, includes 13 subtypes of EDS. Although other forms of the condition may exist, they are extremely rare and are not well-characterized.
Signs and Symptoms
There are 13 types of Ehlers-Danlos syndromes (EDS), with a significant overlap in features:
Hypermobile EDS - characterized primarily by joint hypermobility affecting both large and small joints, which may lead to recurrent joint dislocations and subluxations (partial dislocation). In general, people with this type have soft, smooth and velvety skin with easy bruising and chronic pain of the muscles and/or bones.
Classical EDS - associated with extremely elastic (stretchy), smooth skin that is fragile and bruises easily; wide, atrophic scars (flat or depressed scars); and joint hypermobility. Molluscoid pseudotumors (calcified hematomas over pressure points such as the elbow) and spheroids (fat-containing cysts on forearms and shins) are also frequently seen. Hypotonia and delayed motor development may occur.
Vascular EDS - characterized by thin, translucent skin that is extremely fragile and bruises easily. Arteries and certain organs such as the intestines and uterus are also fragile and prone to rupture. People with this type typically have short stature; thin scalp hair; and characteristic facial features including large eyes, a thin nose, and lobeless ears. Joint hypermobility is present, but generally confined to the small joints (fingers, toes). Other common features include club foot; tendon and/or muscle rupture; acrogeria (premature aging of the skin of the hands and feet); early onset varicose veins; pneumothorax (collapse of a lung); recession of the gums; and a decreased amount of fat under the skin.
Kyphoscoliosis EDS - associated with severe hypotonia at birth, delayed motor development, progressive scoliosis (present from birth), and scleral fragility. Affected people may also have easy bruising; fragile arteries that are prone to rupture; unusually small corneas; and osteopenia (low bone density). Other common features include a "marfanoid habitus" which is characterized by long, slender fingers (arachnodactyly); unusually long limbs; and a sunken chest (pectus excavatum) or protruding chest (pectus carinatum).
Arthrochalasia EDS - characterized by severe joint hypermobility and congenital hip dislocation. Other common features include fragile, elastic skin with easy bruising; hypotonia; kyphoscoliosis (kyphosis and scoliosis); and mild osteopenia.
Dermatosparaxis EDS - associated with extremely fragile skin leading to severe bruising and scarring; saggy, redundant skin, especially on the face; and hernias.
Brittle Cornea Syndrome (BCS) - characterized by thin cornea, early onset progressive keratoglobus; and blue sclerae.
Classical-like EDS (clEDS) - characterized by skin hyperextensibility with velvety skin texture and absence of atrophic scarring, generalized joint hypermobility (GJH) with or without recurrent dislocations (most often shoulder and ankle), and easily bruised skin or spontaneous ecchymoses (discolorations of the skin resulting from bleeding underneath).
Spondylodysplastic EDS (spEDS) - characterized by short stature (progressive in childhood), muscle hypotonia (ranging from severe congenital, to mild later-onset), and bowing of limbs.
Musculocontractural EDS (mcEDS) - characterized by congenital multiple contractures, characteristically adduction-flexion contractures and/or talipes equinovarus (clubfoot), characteristic craniofacial features, which are evident at birth or in early infancy, and skin features such as skin hyperextensibility, easy bruisability, skin fragility with atrophic scars, increased palmar wrinkling.
Myopathic EDS (mEDS) - characterized by congenital muscle hypotonia, and/or muscle atrophy, that improves with age, Proximal joint contractures (joints of the knee, hip and elbow); and hypermobility of distal joints (joints of the ankles, wrists, feet and hands).
Periodontal EDS (pEDS) - characterized by severe and intractable periodontitis of early onset (childhood or adolescence), lack of attached gingiva, pretibial plaques; and family history of a first-degree relative who meets clinical criteria.
Cardiac-valvular EDS (cvEDS) - characterized by severe progressive cardiac-valvular problems (aortic valve, mitral valve), skin problems (hyperextensibility, atrophic scars, thin skin, easy bruising) and joint hypermobility (generalized or restricted to small joints). You can view more detailed information about all 13 types of EDS on the Ehlers-Danlos Society's website. Other forms of the condition may exist but are extremely rare and are not well-characterized.
Ehlers-Danlos syndromes (EDS) are genetic disorders that can be caused by mutations in several different genes, including COL5A1, COL5A2, COL1A1, COL3A1, TNXB, PLOD1, COL1A2, FKBP14 and ADAMTS2. However, the underlying genetic cause is unknown in some families.
- Mutations in these genes usually change the structure, production, and/or processing of collagen, or proteins that interact with collagen. Collagen provides structure and strength to connective tissues throughout the body. A defect in collagen can weaken connective tissues in the skin, bones, blood vessels, and organs, resulting in the signs and symptoms of EDS.
The inheritance pattern of Ehlers-Danlos syndromes (EDS) varies by subtype.
Autosomal dominant types
The arthrochalasia EDS, classical EDS, hypermobile EDS, periodontal EDS, some cases of myopatic EDS, and vascular forms of EDS usually have an autosomal dominant pattern of inheritance. This means that to be affected, a person needs to have a change (mutation) in only one copy of the disease-causing gene in each cell.
In some cases, a person with these forms of EDS inherits the mutation from an affected parent. Other cases may result from new (de novo) mutations in the gene; these cases occur in people with no family history of EDS. Each child of a person with autosomal dominant EDS has a 50% chance of inheriting the mutation.
Autosomal recessive pattern
- The dermatosparaxis EDS, kyphoscoliosis EDS, classical-like EDS, cardiac-vascular EDS, brittle cornea syndrome, spondylodysplastic EDS, musculocontractural EDS, and some cases of myopatic EDS are inherited in an autosomal recessive pattern.
- This means that have any of these types of EDS, a person must have a mutation in both copies of the disease-causing gene in each cell.
- The parents of an affected person usually each carry one mutated copy of the gene and are referred to as carriers.
- Carriers typically do not show signs or symptoms of the condition.
- When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier.
- A diagnosis of the Ehlers-Danlos syndromes (EDS) is typically based on the presence of characteristic signs and symptoms. Depending on the subtype suspected, some of the following tests may be ordered to support the diagnosis:
- Collagen typing, performed on a skin biopsy, may aid in the diagnosis of vascular type, arthrochalasia type, and dermatosparaxis type. People with EDS often have abnormalities of certain types of collagen.
- Genetic testing is available for many subtypes of EDS; however, it is not an option for most families with the hypermobility type.
- Imaging studies such as CT scan, MRI, ultrasound, and angiography may be useful in identifying certain features of the condition.
- Urine tests to detect deficiencies in certain enzymes that are important for collagen formation may be helpful in diagnosing the kyphoscoliosis type.
- The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition.
- The intended audience for the GTR is health care providers and researchers.
- Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Individual with EDS displaying hypermobile metacarpophalangeal joints
- The outcome for individuals with EDS depends on the specific type of EDS they have.
- The vascular type is typically the most severe form of EDS and is often associated with a shortened lifespan.
- People affected by vascular EDS have a median life expectancy of 48 years and many will have a major event by age 40.
- The lifespan of people with the kyphoscoliosis form is also decreased, largely due to the vascular involvement and the potential for restrictive lung disease.
- Symptoms vary in severity, even in the same disorder, and the frequency of complications varies.
- Some people have negligible symptoms, while others are severely restricted in daily life.
- Extreme joint instability, chronic musculoskeletal pain, degenerative joint disease, frequent injuries, and spinal deformities may limit mobility.
- Severe spinal deformities may affect breathing.
- In the case of extreme joint instability, dislocations may result from simple tasks such as rolling over in bed or turning a doorknob.
- Secondary conditions such as autonomic dysfunction or cardiovascular problems, occurring in any type, can affect prognosis and quality of life. Severe mobility-related disability is seen more often in hypermobile EDS than in classical EDS or vascular EDS
- Although all types of EDS are potentially life-threatening, most people have a normal lifespan.
- Ehlers–Danlos syndromes are inherited disorders estimated to occur in about one in 5,000 births worldwide.
- EDS may be far more common than the currently accepted estimate due to the wide range of severities with which the disorder presents.
- The prevalence of the disorders differs dramatically.
- The most commonly occurring is hypermobile EDS, followed by classical EDS. The others are very rare.
- Fewer than 10 infants and children with dermatosparaxis EDS have been described worldwide.
- Some types of EDS are more common in Ashkenazi Jews.