Ehlers-Danlos Syndrome (EDS) encompasses a group of inherited conditions that affect connective tissues throughout the body. These tissues provide support, structure, and protection to various body parts, including organs. EDS disorders stem from issues that prevent connective tissue from functioning as it should, with collagen being a primary protein affected.
Collagen’s Role in the Body
Collagen stands as the most abundant protein in the human body. It serves as a fundamental building block for skin, muscles, bones, tendons, ligaments, and other connective tissues. Collagen is also present in organs, blood vessels, and the intestinal lining.
The main function of collagen is to provide structure, strength, and support throughout the body. Collagen also provides a protective covering for organs, gives skin structure and elasticity, and assists in blood clotting. This protein’s triple helix structure gives it high tensile strength, making it suitable for rigid tissues like bone and compliant tissues such as tendons.
How Collagen Dysfunction Leads to Ehlers-Danlos Syndrome
Ehlers-Danlos Syndrome results from genetic mutations that disrupt the body’s ability to produce collagen correctly. These genetic changes can affect the production, processing, or structure of collagen or other proteins that interact with collagen. Over 20 different genetic mutations have been identified that can lead to EDS.
When collagen is faulty, it prevents the formation of strong, stable connective tissue. This can lead to weaker and more flexible connective tissue than typically observed. The specific mutation determines which parts of the body are affected, and the resulting impaired collagen leads to the characteristic fragility and hyperextensibility seen in individuals with EDS.
Major Types of Ehlers-Danlos Syndrome Linked to Collagen Defects
There are 13 recognized types of Ehlers-Danlos Syndrome, with many linked to specific collagen defects. Classical EDS (cEDS) is associated with alterations in genes that instruct the body to make Type V collagen, and sometimes Type I collagen. These genetic changes can lead to a lack of Type V collagen, causing disordered packing of collagen fibers and less effective connective tissue.
Vascular EDS (vEDS) is considered a more serious type due to its association with defects in Type III collagen. This type is caused by mutations in the COL3A1 gene. These mutations can result in either faulty Type III collagen or a reduced amount of normal Type III collagen, making blood vessels and hollow organs prone to tearing, which can be life-threatening.
Hypermobile EDS (hEDS) is the most common type. Its exact genetic cause is not consistently identified, though it is widely believed to involve subtle defects in collagen structure or processing. The symptoms of hEDS, such as joint instability and tissue fragility, suggest that collagen and connective tissue play a significant role in its manifestation.
Common Manifestations of Impaired Collagen
Impaired collagen structure and function lead to several common physical characteristics in individuals with EDS. Joint hypermobility is a hallmark feature. Loose or unstable collagen results in overly flexible joints that can dislocate or subluxate easily, leading to pain and injuries.
Skin hyperextensibility is another common manifestation. Collagen defects cause the skin to be soft, velvety, and fragile, making it susceptible to easy bruising and splitting even from minor trauma. Wounds often heal slowly and can leave wide, “cigarette paper” scars.
Tissue fragility extends beyond the skin, affecting various organs and blood vessels. This can lead to a higher risk of organ and blood vessel fragility. While chronic pain and fatigue are frequently experienced, these are often secondary effects stemming from the widespread weakness of connective tissue.