History of EDS Types
The Difference Between the Numbered and Name Classifications
When learning about Ehlers-Danlos Syndrome there are two different classifications that are frequently referenced.
There are currently six recognized classifications of Ehlers-Danlos Syndrome (EDS); Hypermobile, Classical, Vascular, Kyphoscoliosis, Athrochalasia, and Dermatosparaxis. However, prior to 1997 there were eleven identified types. It can be confusing when researching information about EDS since both systems of classification are encountered.
History
Most clinical observations of people with unusual physical flexibility were detailed as early as the late 1800s, though sporadic accounts can be found from over 2000 years earlier. For example, Hippocrates detailed some cases among Nomads and Scythians as early as 400 BC.
Two physicians, Edvard Ehlers and Henri-Alexandre Danlos, both presented patients who exhibited unusual skin and joint properties to the Paris Society of Syphilology and Dermatology in 1899 and 1908 respectively. Their work to understand their patients’ unusual symptoms led to the recommendation in 1936 that the syndrome should be named Ehlers-Danlos.
By the mid 1900s EDS had gained recognition. In the late 1960s the first major attempt to organize the symptoms into categories resulted in the Berlin nosology. This system of classification provided eleven different categories based primarily on clinical observations. These categories were named Type I through Type XI.
In 1997 the Ehlers-Danolos National Foundation in the US and the Ehlers-Danlos Support Group in the UK brought together an international group of specialists to re-examine the Berlin nosology. The result is the Villefranche classification. The Villefranche classification reorganizes the previous ten types into six based on both clinical observations and genetic traits. Diagnosis is based on inheritance, major and minor clinical observations, and known connections to specific genes.
Connections
When looking for information about EDS it is common to encounter both classifications. Though the Villefranche classification is used in newer medical publications, older documents and references provide the Berlin nosology. A general description of each type as I relates to the previous classification and it’s general diagnosis criteria follows.
Classical EDS reclassifies types I and II. It is genetically inherited as a dominant trait from the genes COL5A1 and COL5A2. Major clinical symptoms include skin hyperextensibility, joint hypermobility, easy bruising and fragile skin with atrophic scars. Type VIII is also similar, but considered very rare.
Hypermobile EDS reclassifies type III. It is genetically inherited as a dominant trait, but the genes involved are still unknown. Major clinical symptoms include joint hypermobility with subluxations and dislocations and mild cutaneous signs and symptoms.
Vascular EDS reclassifies type IV. It is genetically inherited as a dominant trait from the gene COL3A1. The only deadly form of EDS, its major clinical symptoms include the rupture of organs including the arteries, intestine and uterus, translucent skin and typical facial features.
Kyphoscoliosis EDS reclassifies type VI. It is genetically inherited as a recessive trait from gene PLOD1. Its major clinical symptoms include joint hypermobility, ocular symptoms, kyphoscoliosis and muscle hypotonia.
Arthrochalasis EDS reclassifies type VII A and B. It is genetically inherited as a dominant trait from genes COL1A1 and COL1A2. Its major clinical symptoms include congenital hip dislocation, severe joint hypermobility with dislocations and a short stature.
Dermatosparaxis EDS reclassifies type VII C. It is genetically inherited as a recessive trait from gene ADAMST-2. Its major clinical symptoms include severe skin fragility and cutis laxa.
The remaining types from the Berlin nosology include:
- Type V, which is found in only one known family
- Type IX, which was reclassified as “Occipital Horn syndrome”
- Type X, which is found in only one known family
- Type XI, which was reclassified as “Familial Joint Hypermobility syndrome”
References:
Ehlers-Danlos National Foundation
