The Hypermobility Type of EDS is characterized by loose joints and chronic joint pain. This form of Ehlers-Danlos Syndrome was formerly called type III. Ehlers-Danlos Syndrome, Hypermobility Type is a subtype of Ehlers-Danlos Syndrome.
The most common sign of this condition is an unusually large range of joint movement, called hypermobility. Both large and small joints are unstable, and certain joints (such as the shoulder, knee, and jaw) tend to dislocate frequently. Chronic joint and limb pain often begins early in life. People with this condition may have skin that is soft, velvety, or stretchy; however, skin symptoms vary among people. Many affected people also have a condition called mitral valve prolapse, which affects blood flow between the chambers of the heart.
The Hypermobility Type is the most co mmon form of Ehlers-Danlos Syndrome. The Hypermobility Type of Ehlers-Danlos Syndrome is most often inherited in an autosomal dominant pattern, which means one copy of the altered gene is sufficient to cause the disorder. In these cases, family members in each generation are usually affected, but the features of the condition may vary.
In some families, a recessive pattern of inheritance may be possible. This inheritance pattern means that two copies of the gene must be altered for a person to be affected by the disorder. Most often, the parents of a child with an autosomal recessive disorder are not affected but are carriers of one copy of the altered gene
Clinical diagnostic criteria and a revised nomenclature for all forms of Ehlers-Danlos Syndrome (EDS) were proposed by [Beighton et al 1998]. EDS, Hypermobility Type is distinguished from EDS, Classical Type chiefly by milder and fewer skin and soft tissue manifestations. The diagnosis of EDS, Hypermobility Type is based entirely on clinical evaluation and family history. The criteria listed below reflect those proposed by [Beighton et al 1998] as modified by the author's experience.
Major Diagnostic Criteria for the Hypermobility Type or EDS
- Joint hypermobility, which usually is confirmed by a score of five or more on the nine-point Beighton scale
[Beighton et al 1973], including:
-One point for passive dorsiflexion of each fifth finger >90º
-One point for passive apposition of each thumb to the flexor surface of the forearm
-One point for hyperextension of each elbow >10º
-One point for hyperextension of each knee >10º
-One point for ability to place the palms on the floor with the knees fully extended
- Soft or velvety skin with normal or slightly increased
Skin hyperextensibility is assessed at a site lacking excess or loose skin and without evidence of prior trauma by gently pulling until resistance is met. Extensor surfaces of joints should not be used because of the presence of excess skin. An ideal location is the volar surface of the forearm, where the upper limit of normal is approximately 1-1.5 cm.
- Absence of skin or soft tissue fragility, which is suggestive of other types of EDS. Examples include:
-Spontaneous or easily induced skin cuts or tears
-Spontaneous or easily induced tears or ruptures of tendons, ligaments, vessels, or other internal organs
-Atrophic ("cigarette paper") scars (although mildly atrophic scars are sometimes seen in the hypermobility type, especially in areas subject to physical stress, such as extensor surfaces and the abdominal wall)
- Surgical complications, such as incisional hernia, wound dehiscence, or sutures tearing through tissues and failing to hold
Minor Diagnostic Criteria for the Hypermobility Type of EDS
- Family history of similar features without significant skin or soft tissue fragility in a pattern consistent with autosomal dominant inheritance
- Recurrent joint dislocations or subluxations
- Chronic joint or limb pain
- Functional bowel disorders (functional gastritis, irritable bowel syndrome)
- Neurally mediated hypotension or postural orthostatic tachycardia
The sensitivity and specificity of examination for joint hypermobility is dependent in part on the individual's age, gender, and medical history.
- Young children (approximately five years of age or younger) tend to be very flexible and are therefore difficult to assess.
- Women are, on average, more flexible than men
- Older individuals tend to lose flexibility, and post-surgical or arthritic joints often have reduced range of motion. A history of former joint laxity or clinical demonstration of substantial laxity in multiple joints is sometimes accepted in lieu of a positive Beighton score in such cases, if the family history and other minor criteria are strongly suggestive
There is disagreement as to whether the "benign familial articular hypermobility syndrome" is identical to EDS, hypermobility type or represents a unique condition [Grahame 1999]. The distinction is subtle and relates to degree of joint complications and presence or absence of skin manifestations. However, first-degree relatives of probands with EDS, Hypermobility Type often have relatively asymptomatic joint laxity and mild or absent skin manifestations. Therefore, the benign hypermobility syndrome is included as EDS, Hypermobility Type for this review.
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about Ehlers-Danlos Syndrome, should consult with a qualified healthcare professional.