Article - Types of EDS

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Types of Ehlers-Danlos Syndrome

Ehlers- Danlos Syndrome (EDS) is a heterogeneous group of heritable

connective tissue disorders characterized by articular hypermobility, skin

extensibility and tissue fragility. There are six major types of EDS. The

different types of EDS are classified according distinct features.

Classical Type

Marked skin hyperextensibility with widened atrophic scars and joint

hypermobility are found. The skin manifestations range in severity from

mild to severe expression. The skin is smooth and velvety with the evidence

of tissue fragility including; hiatal hernia, anal prolapse in childhood and

cervical insufficiency. Hernias may be a post-operative complication. Also

evident are molluscoid pseudotumors frequently found over pressure points

and subcutaneous spheroids which are mobile and palpable on the forearms and

shins.

Complications of joint hypermobility include sprains,

dislocations/subluxations and pes planus. Recurrent subluxations are

common in the shoulder, patella and temporomandibular joints. Muscle

hypotonia, delayed gross motor development may be evident.

Abnormal electrophoretic mobility of the proa 1(V) or proa 2(V) chains of

collagen type V has been detected. Autosomal dominant inheritance.

Hypermobile Type

The skin involvement (hyperextensible and/or smooth, velvety skin) as well

as bruising tendencies are both variable. Joint hypermobility is the

dominant clinical manifestation. Generalized joint hypermobility that

affects large and small joints is evident in Hypermobile Type EDS.

Recurring joint dislocations are common occurrences. Certain joints, such

as the shoulder, patella, and temporomandibular joint dislocate frequently.

Chronic joint and limb pain is a common complaint amongst individuals with

Hypermobile Type EDS. Skeletal X-rays are normal. Musculoskeletal pain is

early onset, chronic and may be debilitating. The anatomical distribution

is wide, tender points are often elicited.

To date, researchers have identified no distinctive biochemical collagen

finding. Autosomal dominant inheritance.

Vascular Type

Thin translucent skin reveals the subcutaneous venous pattern, and is

particularly apparent over the chest and abdomen. Facial appearance is

characteristic in some affected individuals. A decrease in subcutaneous

tissue, particularly in the face and extremities is evident. Minor trauma

can lead to extensive bruising. Arterial/intestinal/uterine fragility or

rupture commonly arise in this type of EDS. Spontaneous arterial rupture

has a peak incidence in the third or fourth decade of life, but may occur

earlier. Midsize arteries are commonly involved. Arterial rupture is the

most common cause of sudden death. Life expectancy is shortened with a

majority of individuals.

Joint hypermobility is usually limited to the digits. Tendon and muscles

rupture can occur. Talipes equinovarus is frequently seen at birth. Other

manifestations that may be found in include: acrogeria; early onset varicose

veins; arteriovenous, carotid-cavernous fistula;

pneumothorax/pneumohemothorax; gingival recession and complications during

and after surgery.

Vascular Type EDS is caused by structural defects in the proa` 1 (III) chain

of collagen type III encodes by COL3A1. Autosomal dominant inheritance.

Kyphoscoliosis Type

Generalized joint laxity and severe muscle hypotonia at birth are seen in

this type of EDS. Muscular hypotonia can be very pronounced and leads to

delayed gross motor development. Individuals present with scoliosis at

birth that is progressive. The phenotype is most often severe, frequently

resulting in the loss of ambulation in the second or third decade. Scleral

fragility may lead to rupture of the ocular globe after minor trauma.

Tissue fragility including atrophic scars and easy bruising may be seen.

Spontaneous arterial rupture can easily occur. Other findings may include:

marfanoid habitus; microcornea; and radiologically considerable osteopenia.

Kyphoscoliosis Type EDS is the result of a deficient lysyl hydroxylase

(PLOD). Autosomal recessive inheritance.

Arthrochalasia Type

Congenital hip dislocation is present in all and severe generalized joint

hypermobility with recurrent subluxations; skin hyperextensibility with easy

bruising, tissue fragility including atrophic scars; muscle hypotonia;

kyphoscoliosis and radiologically mild osteopenia.

Arthrochalasia Type EDS is caused by mutations leading to deficient

processing of the amino-terminal end of proa 1(I) [type A] or proa 2 (I)

[type B] chains of collagen type I. Autosomal dominant inheritance.

Dermatosparaxis Type

Individuals demonstrate severe skin fragility bruising. Wound healing is

not impaired and the scars are not atrophic, skin texture is soft and

doughy. Sagging, redundant skin is evident. The redundancy of facial skin

results in an appearance resembling cutis laxa. Large hernias (umbilical,

inguinal) may also be seen.

Dermatosparaxis Type EDS is caused by a deficiency of procollagen I

N-terminal peptidase. Autosomal recessive inheritance.

Prognosis

The prognosis of EDS depends on the specific type. Life expectancy can be

shortened with the Vascular Type of EDS due to the possibility of organ and

vessel rupture. Life expectancy in all other types is normal.

Reference:

Beighton, P., De Paepe, A., Steinmann, B., Tsipouras, P., & Wenstrup, R. (in

press). Ehlers-Danlos Syndrome: Revised Nosology, Villefranche, 1997.

American Journal of Medical Genetics.