hEDS & HSD Research: The Search for Causes and Diagnostic Tests

The Ehlers-Danlos Society is funding a series of vital research studies to further the understanding of hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD), with the goal of finding the underlying causes for these conditions, as well as developing diagnostic tests. This falls under our GAP Research priority — looking into the genotype and phenotype of individuals living with these conditions.   

Hypermobile EDS (hEDS) remains the only type of the thirteen classified Ehlers-Danlos syndromes that cannot be confirmed through a genetic test. The genes associated with hEDS are currently unknown, and diagnosis is made on a clinical basis.  

If we can achieve a better understanding of the underlying genetics and the gene expression abnormalities, we may be able to develop diagnostic tests and find more specific treatments for hypermobile EDS — and, potentially, the hypermobility spectrum disorders. 

There have been great strides in biotechnology over the last two decades and the ability to understand and find treatments for genetic syndromes is at a turning point. Detailed research into the underlying issues causing hEDS and HSD will help determine where to target therapy.  

Research Studies Funded and Led by The Ehlers-Danlos Society 

In 2018, The Ehlers-Danlos Society launched its groundbreaking $1 million Hypermobile Ehlers-Danlos Genetic Evaluation (HEDGE) Study. Never before had there been a worldwide collaborative effort of this magnitude devoted to finding the underlying genetic markers for hEDS. The study will also look for other blood findings that may add to our understanding of hEDS and help in the search for a diagnostic test. 

From 2019-2021, the HEDGE study recruited, screened, and secured blood samples from 1000 individuals who have been diagnosed with hEDS by the most recent clinical criteria established in 2017.  

When the COVID pandemic came into force in early 2020, the study team quickly adapted to virtually enrolling the remaining people needed and this is being rolled out in 2021.  

Based on research and expert opinion, to date there have only been fewer than 200 people with hypermobile EDS who have had whole-genome sequencing, and fewer than 500 who have had whole-exome sequencing with EDS around the world. The Broad Institute in Boston is currently performing whole-genome sequencing of the 1000 DNA samples from the HEDGE study, and when all the samples have been sequenced, two teams will begin the data evaluation phase, which is expected to require two years.  

Joel Hirschhorn, MD, Ph.D., Concordia Professor of Pediatrics and Professor of Genetics, Harvard Medical School, will lead the team in Boston, Massachusetts. Christina Laukaitis, MD, PhD, Associate Professor at the University of Illinois, and the Carle Illinois College of Medicine, will lead a team based in Illinois. 

In recent months there have been some exciting announcements from Norris Labs at MUSC Health about finding a candidate gene related to hEDS that will be published soon. HEDGE is different from this work in that it is the first and only population study in hypermobile Ehlers-Danlos syndrome to sequence 1000 people. 

Unlike studies of specific families, HEDGE is designed to provide information about causative genetic variants in the hEDS population by using statistical methods to identify variants that occur more commonly in hEDS. Studies in specific families have uncovered variants that appear to cause hEDS findings in a family, but no studies to date have shown findings that are thought to affect more than about 2% of people with hEDS. HEDGE is directed at understanding the remaining 98%. 

The HEDGE analysis team announced in May 2023 that the data are in and analysis is underway of 1021 whole-genome sequences. The analysts are very happy with the data quality and are working to identify meaningful genetic variants. To do this requires a painstakingly careful and rigorous process, but they are making steady progress.   

We would like to especially thank each and every volunteer who has taken part in the study and donated their time and DNA to help research for our futures.   

Please remember that HEDGE is a research study and not a diagnostic test, so participants will not hear any feedback or results until the end of the analysis in approximately 18–24 months. However, any participants found to have genetically defined types of EDS will be contacted directly.   

If the study identifies a genetic variant that seems to be responsible for hEDS, we will notify the participants who carry that variant and provide additional information. For more details about the return of results, please refer to the consent form. If we do not identify any relevant genetic variants in your participation, we will not communicate further regarding your involvement in the study.   

Please stay updated on HEDGE research by visiting our website, joining our CONNECT newsletter, and following us on social media. 

In December 2021, The Ehlers-Danlos Society announced $260,000 to advance research to accelerate diagnostic tools for hEDS.  


There is currently an unmet clinical need for the development of sensitive and unbiased diagnostic tools for hEDS. Dr. Chip Norris at the Medical University of South Carolina, Principal Investigator, and Dr. Clair Francomano of IU University, Co-Investigator, are leading a biomarker discovery study in collaboration with The Ehlers-Danlos Society Hypermobility Network. 

This research study will seek to lead to the development of an accurate and rapid diagnostic test that can be accessible for all individuals living with hEDS, globally, overcoming the many barriers people with hEDS face in receiving a proper diagnosis. 

Dr. Norris and Dr. Francomano will perform an unbiased proteomic biomarker discovery study on 1 milliliter of human plasma samples. The samples will be taken from 50 people who have a clinical diagnosis of hEDS and who are part of The Ehlers-Danlos Society’s HEDGE Study. This data will be compared against 50 healthy age/sex-matched controls. 

In May 2022, The Ehlers-Danlos Society announced $400,000 towards a new comprehensive study of blood and DNA in individuals with HSD and hEDS. This study, made possible through the generosity of donors, is enrolling fifty people with a diagnosis of hEDS and fifty people with a diagnosis of HSD to examine levels of blood proteins, epigenetic marks on DNA, and DNA sequence.   

This will be the largest, most comprehensive examination of blood protein levels to date and may provide insights into the nature of the disorders as well as possibly advance diagnosis and treatment.   

Additionally, the study will examine the way DNA is “marked” in people with hEDS and HSD.  These chemical (epigenetic) marks on DNA serve as an additional layer of information controlling the expression of genes and could be involved in causing these conditions. This will be the first study of such epigenetic marking of DNA in hEDS or HSD.   

The individuals with hEDS participating in this study are part of The Ehlers-Danlos Society’s HEDGE research study and have had whole-genome sequencing, providing the third component of the study.   

The HSD participants, in addition to having protein and epigenetic analysis, will also undergo whole-genome sequencing.  

We are delighted to be collaborating with the following people on these studies:   

  • Dr. Chip Norris, Medical University of South Carolina — Proteomics  
  • Dr. Clair Francomano, IU Health IU University — Proteomics   
  • Dr. Bekim Sadikovic, Western University — Epigenetics  
  • Dr. Joel Hirschhorn, The Broad Institute of MIT and Harvard, and Dr. Christina Laukitis, Carle Urbana on Windsor — Whole Genome Sequencing analysis.   

Participants will be selected from The Ehlers-Danlos Society’s DICE Global Registry. 

Additional Studies Funded by The Ehlers-Danlos Society into hEDS and HSD 

Exploring new gene candidates for hEDS. By taking the genetic variants that we identified in hEDS patients, we can validate whether these potential mutations (or variants of unknown significance) are relevant to causing hEDS. Through these studies, new models will be generated that will allow us to test how genotype can correlate with phenotype and various co-morbidities found in the patients. 


Primary Investigator: 

Russell Norris 

Medical University of South Carolina 

Charleston, South Carolina, USA 

2021 – Molecular Studies in hEDS and HSD $1 Million Grant 

Insights into the mechanisms that cause disease in hypermobile EDS (hEDS) remain scarce. An important reason for this is the huge variation in clinical presentation among hEDS patients, which makes it unlikely that a single genetic defect will be responsible to cause this condition, but at the same time, it also makes it hard to pinpoint the exact molecular cause. Nevertheless, given the overlap of clinical symptoms with other EDS subtypes, that lead to abnormalities in the extracellular matrix (ECM), especially with classical EDS (cEDS), it is likely that the mechanisms underlying hEDS also affect the ECM to a certain extent. 

Today, several technological advances make it possible to obtain and investigate large, complete datasets of all the DNA (genome), the RNA (transcriptome), and the proteins (proteome) in a particular tissue or cell type from an individual. It is known that in disease states, changes can be observed at these three levels. However, the extent of these changes in hEDS is currently not known. 

In this study, we will perform these analyses on the skin and skin cells (fibroblasts) from two affected and one non-affected individual from 10 different hEDS families. In addition, we will also include skin and fibroblasts of 15 cEDS patients as a positive control since the genetic defect in these patients is known, and we will also include 10–15 healthy volunteers to compare the findings in hEDS and cEDS patients. Our approach is unique in the fact that we will investigate all datasets (genome, transcriptome, and proteome) for each of the selected individuals. To the best of our knowledge, this is the first time an integrative approach of this kind is applied to investigate this challenging condition. 

The findings resulting from this research will be helpful to understand the defective mechanisms in hEDS, but also in cEDS. Moreover, this approach may result in the identification of (a) prognostic biomarker(s) for disease progression and the development of complications, such as chronic widespread pain or other symptoms. The knowledge obtained from these studies may also be useful for hypermobility spectrum disorder (HSD) patients and patients with other EDS subtypes. These findings may ultimately have an impact on the classification and/or grouping of these patients, eventually resulting in faster diagnosis, more effective management, and better counseling. 

Research grant awarded from The Ehlers-Danlos Society: $200,000
Primary Investigator:
Delfien Syx
Ghent University
Ghent, Belgium 

Complex chronic diseases account for nearly two-thirds of deaths worldwide and most healthcare expenditure in the USA, thereby representing a major challenge to global health in the 21st century. With advances in technology, many promising tools have been created to better utilize precision medicine to improve diagnosis, treatment, and preventive strategies regarding complex comorbid conditions. However, there is a large gap between routine medical practice and the implementation of all these new tools and pipelines, creating a huge hurdle in treating patients with complex chronic conditions. Ehlers-Danlos syndrome, a group of related hereditary disorders that affect connective tissues are prototypical examples of complex chronic diseases, affecting millions of people worldwide. 

EDS hallmark features involve joint hypermobility, soft and hyperextensible skin, abnormal wound healing, and easy bruising. However, the genetic and epigenetic variation can affect the degree of skin hyperextensibility and joint hypermobility and some additional clinical features that differ among EDS subtypes, such as the fragility of soft tissues, vessels, and hollow organs, early-onset periodontal disease, and involvement of the musculoskeletal system. Variations in clinical presentation and symptoms’ severity and the reduction in the degree of hypermobility due to factors such as aging, arthritis, and surgeries can cause ambiguities in clinical recognition between different classes of EDS. The genetic causes of hypermobile EDS (hEDS), the most common type of EDS, and hypermobility spectrum disorders (HSD) are still unknown. 

hEDS/HSD tends to run in families, suggesting a role for genetic predisposition in the development of the disease. Families with hEDS/HSD history also have a high burden of other comorbidities such as chronic fatigue syndrome, post-treatment Lyme disease syndrome, pediatric acute-onset neuropsychiatric syndrome, postural orthostatic tachycardia syndrome, GI disorders, small fiber neuropathy, craniocervical instability, sleep disorders, and anxiety. These indicate that family-based multi-omics studies are extremely valuable in understanding the genetic susceptibilities and molecular basis of hEDS/HSD, as the background genetic variation and environmental exposures are controlled to some extent. Here, we propose to conduct a comprehensive longitudinal multi-omics study on blood samples collected from multiple families with hEDS/HSD. This research will provide a deeper understanding of the underlying genetic and epigenetic risk factors associated with hEDS/HSD. Integrating the multi-omics data with participants’ clinical information will provide a causal mechanistic model of hEDS/HSD and help us to investigate key factors that can be therapeutically targeted or used as biomarkers, as well as insights into pathogenesis and heterogeneity. The long-term goal of this study is to develop novel blood-based biomarkers for more feasible and cost-effective diagnostic and/or prognostic assessment of hEDS/HSD and to identify therapeutic targets and strategies improving patients’ care; we have therefore assembled a team ideally suited to take on this challenge. 

Research grant awarded from The Ehlers-Danlos Society: $200,000
Primary Investigator:
Fereshteh Jahaniani
Stanford University
Palo Alto, USA 

The Ehlers-Danlos syndromes (EDS) are a group of heritable, connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. There is phenotypic and genetic variation among the various thirteen types. The initial genetic findings on EDS were related to changes in collagen but the causes of the many subtypes revealed several genes not involved in collagen production. However, the genetic basis of the hypermobile type of EDS (hEDS) is not known. 

hEDS is the most common type of EDS and involves generalized joint hypermobility, musculoskeletal manifestations, and mild skin involvement along with the presence of several co-morbid conditions. Variability in the spectrum and severity of symptoms and progression of patient phenotype likely depend on a combination of age, gender, lifestyle, and the likely multitude of genes involved in hEDS. 

Our studies were initiated with a large family that presented with inherited hEDS. Through our genetic studies, we were able to identify a mutation in a putative causal gene. This mutation was found in each of the nine affected individuals throughout four generations of the family and none of the non-affected individuals. Since this initial discovery, we have successfully generated a mouse model with the corresponding human mutation. These mice have phenotypes consistent with hEDS, therefore validating the mutation as causative. In this proposal, we wish to add to these studies by uncovering not only how the mutation causes disease, but also identify additional causative mutations in large families with hEDS. These studies will identify why patients have defects in connective tissues and will indicate how we can develop treatments to help those with hEDS. 

Research grant awarded from The Ehlers-Danlos Society: $200,000
Primary Investigator:
Russell Norris
Medical University of South Carolina
Charleston, USA 

Hypermobile Ehlers-Danlos syndrome (hEDS) is characterized by generalized joint hypermobility, musculoskeletal pain, and other systemic manifestations without a known molecular basis. Therefore, its recognition remains an exclusion diagnosis based on a new set of strict clinical criteria. Patients with symptomatic joint hypermobility who did not fulfill these new diagnostic criteria are currently classified as hypermobility spectrum disorders (HSD). 

The present proposal aims to unravel, by integrated molecular, biochemical/physical, and nanoscience approaches, bioactive key molecules, and pathophysiological mechanisms associated with these conditions. We previously demonstrated that hEDS and HSD cells shared a pro-inflammatory matrix-degrading phenotype with a range of cellular features that are typical of myofibroblasts. Cellular proteome profiling of hEDS myofibroblasts revealed changes in the expression of a subset of proteins mainly implicated in cellular metabolism, redox balance, extracellular matrix (ECM) homeostasis, cytoskeleton organization, protein folding into the endoplasmic reticulum, intracellular trafficking, and secretory pathway. Proteome analysis of hEDS cells-derived culture media (CM) discovered altered levels of several ECM structural components (including collagens, fibronectin, and proteoglycans), matrix metalloproteinases and their inhibitors, and further secreted proteins predicted to be located in extracellular vesicles (EVs), which likely contribute to the excessive ECM degradation and concomitant acquisition of the peculiar myofibroblast-like phenotype. Furthermore, preliminary data obtained treating control fibroblasts with patient cells’ CM-derived soluble factors and EVs suggested that both these fractions may act synergistically to induce the disease phenotype. 

In the present project, we plan to corroborate and deepen our previous proteome and secretome findings through targeted in vitro functional studies on interesting, emerged biomolecules both in hEDS and HSD myofibroblasts, to decipher mechanisms of action and functional significance within specific disease pathways to support their diagnostic application and possible future use as therapeutic targets. We also project to dissect the secretome composition of hEDS and HSD myofibroblasts, by fractioning it into soluble macromolecular components (MCs) and different sized-EVs, to uncover specific RNA species (including miRNAs), secreted bioactive mediators, and associated disease pathways that may contribute to the hEDS and HSD pathomechanisms. 

This research, followed by targeted in vivo translational studies on patients’ serum/plasma, should contribute to the elucidation of the etiopathogenesis of hEDS and HSD, offer the possibility to identify potential biomarkers defining whether these disorders are part of a phenotypic spectrum rather than distinct clinical entities and, ultimately, pave the way to the development of targeted therapeutic strategies with a potential benefit for patients’ management. Considering the huge number of hEDS and HSD patients, the project could have a large social and economic impact. Indeed, reaching a definite and certain diagnosis will stop the expensive and lengthy diagnostic process, and the development of targeted therapies will decrease the prescription of ineffective drugs and unnecessary evaluations, improve patients’ quality of life, and alleviate their disabilities. 

Research grant awarded from The Ehlers-Danlos Society: $200,000
Primary Investigator: Marina Colombi, University of Brescia, Brescia, Italy 

Many people consider Ehlers-Danlos syndrome to be one condition. However, our current understanding is more of a family of disorders, each with its own genetic cause and unique features. Recent advances in genetic technology have allowed for the discovery of the causes of several rare types of EDS. Hypermobil EDS (hEDS) is the most common form of EDS, and although updates to the diagnostic criteria in 2017 improved our ability to appropriately diagnose hEDS, they are not perfect. It would be extraordinarily helpful for patients if we were able to understand more about the underlying cause(s). 

Earlier research trying to answer this question suggested that a gene known as TNXB may be responsible for both some cases of hEDS and a different type of EDS known as classic-like EDS (clEDS). It is likely that this is true, but this has proven to be a difficult gene to understand, and at best it represents a very small percentage of hEDS patients. Therefore, much remains to be learned about the causes of hEDS. Previous research has used a method known as whole-exome sequencing (WES) which analyzes only the parts of the human genome that code for protein products and has thus far not been successful in findings causes of hEDS. Current efforts to use whole-genome sequencing (WGS) to investigate the cause of hEDS offer additional potential for gene discovery, but the technology itself has limitations. 

We propose asking the question of the cause of hEDS in diverse ways. First, given the nature of our clinic, we can recruit significant numbers of entire families of affected patients and compare them to other unaffected relatives. This will increase the likelihood that helpful results will be obtained. 

Second, we will use the existing infrastructure of the Genomic Answers for Kids program to evaluate for known genetic disorders which may look like hEDS but have different genetic causes. We have already found several such patients in this study but anticipate that there are more. 

Third, genomic research thus far has generally used next-generation sequencing (NGS) technology for “short read” WES and WGS. NGS produces many small pieces of DNA that are then aligned by computer so that the entire sequence can be analyzed. Because the individual pieces of DNA are so small, there are many areas of the human genome that NGS cannot accurately analyze. 

This study proposes using 3rd generation long-read WGS for patients with a clinical diagnosis of hEDS and no diagnosis found on standard short read WES. Having a longer length for each sequenced DNA strand is beneficial for analyzing areas that NGS is unable to accurately analyze. This includes certain types of spelling errors and larger changes to the structure of the DNA. Fourth, we will use a person’s individual sequence to compare to “normal” references to look for extra pieces of DNA. In conclusion, we feel that the expertise and novel approach that Children’s Mercy Kansas City brings to this project offers significant potential for discovering the causes of hEDS. 

Research grant awarded from The Ehlers-Danlos Society: $200,000
Primary Investigator: Tomi Pastinen, Children’s Mercy Hospital, Kansas City, Missouri. 

2019 – 

Hypermobile Ehlers-Danlos syndrome/hypermobility spectrum disorders (hEDS/HSD) are characterized by generalized joint hypermobility, musculoskeletal pain, and minor systemic manifestations without a known molecular basis. Hence, its recognition remains an exclusion diagnosis based on a new set of clinical criteria. From a point of scientific view, detailed knowledge of the pathogenetic mechanisms is an essential starting point for the development of targeted management/therapies for highly disabling signs that considerably reduce the quality of life and working ability of hEDS/HSD patients. Therefore, unraveling the complexities underlying the etiology of hEDS/HSD and their pathogenetic link with musculoskeletal pain will surely help in having a more feasible diagnostic assessment and/or prognostication of the disorder, and improving the knowledge of mechanisms of musculoskeletal pain generation and chronicization. Musculoskeletal pain is a great burden for the general population in most developed countries. The proposed research may have a translational relevance and impact for the National Health Systems, considering the huge number of hEDS/HSD patients (several hundred patients with hEDS/HSD clinically evaluated in our center) and thus reaching a definite diagnosis will stop the expensive and lengthy diagnostic process for these individuals. Furthermore, the disclosure of the pathogenetic background of these patients will lead to the development of targeted management/therapies that will decrease the prescription of ineffective drugs and unnecessary evaluation, ameliorating patients’ management and treatment of the disease, likely contributing to the improvement of their healthcare. In this scenario, the findings that will derive from the present research activity could address towards future research for the identification of serum diagnostic biomarkers, which might be a promising approach for non-invasive diagnostic tests for hEDS/HSD patients. 

Primary Investigator:
Marina Colombi, PhD
Full Professor of Medical Genetics
Department of Molecular and Translational Medicine Institution 

University of Brescia
Viale Europa, 11 – 25123
Brescia, Italy 


Hypermobility Ehlers-Danlos syndrome (hEDS) is the most common of the 13 EDS subtypes. It is also the only subtype without identified causative genes. This study supports analysis of gene expression (RNAseq) in people with hEDS compared with normal controls. The goal is to identify genes that are differentially expressed in hEDS, thus pointing to relevant pathogenic processes and supporting candidate genes found in whole genome sequencing. 

Primary Investigator:
Christina M. Laukaitis, MD, PhD, FACP, FACMG
Director, Genetic Consultation and Counseling Services, UAHS Center for Applied Genetics and Genomic Medicine 

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