Best model of hypermobility to explain the spectrum


Senior Member
U.S., Earth
Hi everyone,

Doctor Marco Castori a Italian Connective Tissue Disorder specialist wrote this paper which I think explains all the possible phenotypes of connective tissue disorders and how to approach them and study them. This is just a model, but in time it may shed some light on how to understand better this condition.

Castori 2021 said:
Deconstructing and reconstructing joint hypermobility on an evo-devo perspective (Castori, 2021)

Joint hypermobility is a common characteristic in humans. Its non-casual association with various musculoskeletal complaints is known and currently defined "the spectrum". It includes hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD).

hEDS is recognized by a set of descriptive criteria, while HSD is the background diagnosis for individuals not fulfilling these criteria. Little is known about the aetiopathogenesis of the spectrum. It may be interpreted as a complex trait according to the integration model. Particularly, the spectrum is common in the general population, affects morphology, presents extreme clinical variability and is characterized by marked sex bias without a clear Mendelian or hormonal explanation.

Joint hypermobility and the other hEDS systemic criteria are intended as qualitative derivatives of continuous traits of normal morphological variability. The need for a minimum set of criteria for hEDS diagnosis implies a tendency to co-vary of these underlying continuous traits. In evolutionary biology, such a co-variation (i.e. integration) is driven by multiple forces, including genetic, developmental, functional and environmental/acquired interactors. The aetiopathogenesis of the spectrum may be resolved by a deeper understanding of phenotypic variability, which superimposes on normal morphological variability.