Connective Tissue Disorders – Ehlers–Danlos Syndrome

Abstract

Ehlers–Danlos Syndrome (EDS) is a group of connective tissue disorders which are both heterogeneous and heritable. The condition is a result of collagen defects, which include genetic variations and collagen protein processing. Collagen is present in fibrous tissues, such as skin, tendons and ligaments, and is also found in cartilage, blood vessels, the cornea, bones and the gut, highlighting its importance and explaining the varied pathophysiology of collagen conditions. These disorders were classified into six major types based upon the genetic and diagnostic variability and pathophysiology which includes skin hyperextensibility, joint hypermobility and tissue friability, but this classification has recently been amended. Determining the type of EDS an individual suffers from is a multifaceted process which relies on clinical examination as well as multiple laboratory techniques. These include: collagen biochemistry; genetic sequencing of the collagen genes, light microscopy, electron microscopy and urinary cross-link analysis. Diagnosis is important to both identify EDS types, allowing management of the condition, and also to aid psychologically where sufferers can appear fit and healthy but in fact be suffering pain and remain undiagnosed. This chapter aims to give an overview of connective tissue disorders, specifically EDS, and to describe and discuss diagnosing EDS in an NHS diagnostic unit. Giving detail on the techniques involved and the interpretation of results obtained.