Ehlers-Danlos syndrome (EDS) is a group of inherited connective tissue disorders that vary according to clinical and biochemical evidence, inheritance mode, and disorder severity (mild to lethal). The disorder is characterized by joint hyperextension, skin hyperextensibility, easy bruising, tissue friability, bleeding, poor wound healing, subcutaneous nodules, as well as cardiovascular, orthopedic, intestinal, and ocular defects.

There are six types of Ehlers-Danlos syndrome (see table). The frequency of all recognized types of EDS is not exactly known but is estimated to be 1:5000 to 10,000. There is no discernable racial predilection.

Six Types of Ehlers-Danlos Syndrome

Type	Major Characteristic(s)
Classic	Skin hyperextensibility; wide atrophic scars; jointhypermobility
Hypermobility	Joint hypermobility; soft, smooth, velvety skin
Vascular	Arterial/intestinal fragility or rupture; extensive bleeding; thin, translucent skin
Kyphoscoliosis	Joint laxity; severe neonatal hypotonia; scoliosis;progressive scleral fragility or globe rupture
Arthrochalasia	Congenital bilateral hip dislocations; severe jointhypermobility; recurrent subluxations
Dermatosparaxis	Severe skin fragility; saggy, redundant skin

Ehlers-Danlos syndrome is an autosomal inherited disorder. The type of EDS the patient has differs according to the chromosome locus/loci and specific gene(s) abnormality.

Causes of Ehlers-Danlos Syndrome

Type of EDS	Chromosome Locus (Loci)	Gene(s) Abnormality
Classic	9q34.2-34.3; 2q31	COL5A1; COL5A2
Hypermobility	Unknown	Unknown
Vascular	2q31	COL3A1
Kyphoscoliosis	1p36.3-36.2	PLOD1
Arthrochalasia	17q31-22.5; 7q22.1	COL1A1; COL1A2
Dermatosparaxis	5q23-24	ADAMST2

The following signs and symptoms are common to all EDS types: