Types of Ehlers-Danlos Syndrome (EDS)
Ehlers-Danlos syndrome (EDS) is a group of connective tissue disorders. It is classified into 13 types based on the specific symptoms and the affected part(s) of the body. All types of EDS are inherited, either through a dominant gene passed down from one parent or through recessive genes passed down from both parents. Most types of EDS share common symptoms involving the joints, skin and blood vessels; however, each type of EDS presents with definitive characteristics. EDS types vary in severity from mild to life-threatening.
Classical EDS — Joint hypermobility (an unusually large range of motion in the joints) and skin fragility are the most common symptoms of classical EDS. Joint dislocations, sprains and strains are common manifestations. Skin is often smooth and stretchy, and it tears and bruises easily. Acquired scars may be flat and indented below the normal layer of skin tissue. This is one of the most common types of EDS.
Hypermobility EDS — Joint hypermobility is the main symptom of hypermobility EDS. Joint dislocations or subluxations (partial dislocations) are common manifestations and can affect both large and small joints. Chronic pain of the muscles and/or bones may also be present. Like classical EDS, hypermobility EDS is one of the most common types of EDS.
Vascular EDS — Vascular EDS is an especially serious form of EDS. Spontaneous rupture of the arteries, uterus or bowel can occur. Veins are typically very visible through translucent skin. Joint hypermobility may be present but is typically limited to small joints, such as joints in the fingers and toes. Clubfoot may present at birth.
Kyphoscoliosis EDS — The differentiating symptoms of kyphoscoliosis EDS include severe curvature of the spine (scoliosis) and fragile globes of the eyes. Symptoms, such as decreased muscle tone and delayed motor skill development, may be present from birth.
Arthrochalsia EDS — Loose joints and frequent dislocations (especially in the hip joints) are the main symptoms of arthrochalsia EDS. The skin may or may not be affected. Individuals with arthrochalsia EDS are often short in stature.
Dermatosparaxis EDS — A rare type of EDS, dermatosparaxis EDS presents with extremely fragile skin that easily bruises and scars. The skin is typically soft, doughy, and may be saggy, especially on the face.
Classical-like EDS — Classical-like EDS is characterized by stretchy, velvety skin that easily bruises; however, indented scars that can be seen in other types are not present. Joint hypermobility may occur with or without dislocations.
Brittle cornea syndrome (BCS) — Brittle cornea syndrome affects the eyes, including thinning and protrusion of the cornea. The white part of the eye, known as the sclera, may appear blue.
Spondylodysplastic EDS — The differentiating symptoms of spondylodysplastic EDS include decreased muscle tone and bowing of limbs. Individuals with spondylodysplastic EDS are often short in stature.
Musculocontractural EDS — Signs of musculocontractural EDS are typically present at birth and include shortened muscles, clubfoot and craniofacial features, such as an increased distance between the eyes, small mouth and low-set ears. Stretchy and fragile skin may also be present.
Myopathic EDS — Myopathic EDS presents with decreased muscle tone or muscle atrophy at birth but typically improves over time. Other symptoms include limited range of motion in the knees, hips and elbow joints and hypermobility of the ankles, wrists, feet and hand joints.
Periodontal EDS — Periodontal EDS is characterized by severe periodontitis (gum disease) that begins in childhood or adolescence. A lack of attachment between the gum tissue and teeth may also be present.
Cardiac-valvular EDS — Severe and progressive problems with heart valves (specifically, the aortic valve and mitral valve) are the main symptoms of cardiac-valvular EDS. Skin problems and loose joints may also occur; however, joint hypermobility is generally found in small joints only.