Ehlers Danlos Syndrome currently has 14 subtypes, and 13 of those have genetic variants identified. hEDS, however, does not. hEDS is by far the most common form of EDS, and it’s presentation is quite heterogeneous. So, while most folks realize that there are probably multiple genes causing the different presentations of hEDS, what fewer people realize is that a number of doctors, researchers, and patients also believe that there may also be some very possible non-genetic factors behind many instances of hEDS/HSD as well.
This continually-in-progress masterpost will be where I collect peer-reviewed articles on this subject as I come across them. I haven’t taken a deep-dive into the research to try to find everything out there, so this is absolutely NOT a list of everything that exists, and please do leave a comment to share any relevant articles you know about!
Articles:
- Catabolism of Intact Type VI Collagen Microfibrils: Susceptibility to Degradation by Serine Proteinases (1993) (PDF Link)
“We report that intact type VI collagen is catabolized by the serine proteases but is resistant to degradation by the metalloproteinases. This is the first indication of intact type VI collagen degradation and implicates cells which are major components of the inflammatory response.”
“Considering the location of mast cells in connective tissues and the recently recognized role of mast cells in disorders in which connective tissue degradation is a key event, e.g., rheumatoid arthritis, it is thus likely that tryptase may contribute to extracellular matrix-degrading processes in vivo.”
- Mast cell tryptase and photoaging: possible involvement in the degradation of extra cellular matrix and basement membrane proteins (2007) (PDF Link)
“Our studies of substrate-embedded zymography indicated the possibility of direct cleavage of collagen type IV and I by tryptase and results showed two possibilities of contribution of mast cell tryptase to ECM [extracellular matrix] degradation (Fig. 7). First, tryptase may activate the latent ECM-degrading proteases to their active forms and degrade the ECM components. Secondly, tryptase may degrade directly of ECM components.”
“In addition to reporting fatigue, muscle pain and joint pain, the veterinarian in this case report experienced a progressive increase in joint laxity resulting in a diagnosis at 2 major medical centers of hyperhypermobile Ehlers–Danlos syndrometype III). Recent research supports a potential role for mast cell activation and dysregulation in a subset of non-genetically mediated EDS patients with joint hypermobility syndrome.[6] In addition to the lung and gastrointestinal tract, mast cells are prevalent in cutaneous tissues throughout the body.[6] In the context of a plausible pathogenesis, a long-standing Bartonella spp. infection, accompanied by chronic mast cell activation could potentially contribute to ongoing damage to connective tissues; thereby resulting in clinical findings indicative of EDS.”
