Chronic Pain and Joint Hypermobility: A Brief Diagnostic Review for Clinicians and the Potential Application of Infrared Thermography in Screening Hypermobile Inflamed Joints.

Joint hypermobility syndromes, particularly chronic pain associated with this condition, including Hypermobile Ehlers-Danlos Syndrome (hEDS) and Hypermobility Spectrum Disorders (HSD), present diagnostic challenges due to their multifactorial origins and remain poorly understood from biomechanical and genomic-molecular perspectives. Recent diagnostic guidelines have differentiated hEDS, HSD, and benign joint hypermobility, providing a more objective diagnostic framework. However, incorrect diagnoses and underdiagnoses persist, leading to prolonged journeys for affected individuals. Musculoskeletal manifestations, chronic pain, dysautonomia, and gastrointestinal symptoms illustrate the multifactorial impact of these conditions, affecting both the physical and emotional well-being of affected individuals. Infrared thermography (IRT) emerges as a promising tool for joint assessment, especially in detecting inflammatory processes. Thermal distribution patterns offer valuable insights into joint dysfunctions, although the direct correlation between pain and inflammation remains challenging. The prevalence of neuropathies among hypermobile individuals accentuates the discordance between pain perception and thermographic findings, further complicating diagnosis and management. Despite its potential, the clinical integration of IRT faces challenges, with conflicting evidence hindering its adoption. However, studies demonstrate objective temperature disparities between healthy and diseased joints, especially under dynamic thermography, suggesting its potential utility in clinical practice. Future research focused on refining diagnostic criteria and elucidating the underlying mechanisms of hypermobility syndromes will be essential to improve diagnostic accuracy and enhance patient care in this complex and multidimensional context.

The use and effectiveness of exercise for managing postural orthostatic tachycardia syndrome in young adults with joint hypermobility and related conditions: A scoping review.

PURPOSE: Postural Orthostatic Tachycardia Syndrome (POTS) is a form of dysautonomia. It may occur in isolation, but frequently co-exists in individuals with hypermobile variants of Ehlers-Danlos Syndrome (EDS) and related conditions (chronic fatigue syndrome [CFS] and fibromyalgia). Exercise is recommended for non-pharmacological POTS management but needs to be individualised. This scoping review explores the current literature on use and effectiveness of exercise-based management for POTS, with specific focus on individuals with joint hypermobility and related conditions who experience hypermobility, and/or pain, and/or fatigue. METHODS: A systematic search, to January 2023, of Medline, EMBASE, AMED, CINAHL and the Cochrane library was conducted. Studies that reported on adolescents and adults who had been diagnosed with POTS using standard criteria and underwent an exercise-based training intervention were included. RESULTS: Following full-text screening, 10 articles were identified (2 randomised control trials, 4 comparative studies and 4 case reports). One comparative study reported a small subset of participants with EDS and one case report included an individual diagnosed with CFS; the remainder investigated a wider POTS population. Overall, 3 months of endurance followed by resistance exercise, graduating from the horizontal-to-upright position reduced POTS symptoms and improved quality-of-life. CONCLUSION: The findings highlight a paucity of higher-level studies documenting exercise for POTS management in people with joint hypermobility and related conditions. Results from the wider POTS population demonstrate exercise is safe and effective. Large, well-designed clinical studies exploring exercise for POTS management adapting to meet the complex musculoskeletal and non-musculoskeletal features of symptomatic joint hypermobility are needed.

Copper Toxicity Associated With an ATP7A-Related Complex Phenotype.

BACKGROUND: The ATP7A gene encodes a copper transporter whose mutations cause Menkes disease, occipital horn syndrome (OHS), and, less frequently, ATP7A-related distal hereditary motor neuropathy (dHMN). Here we describe a family with OHS caused by a novel mutation in the ATP7A gene, including a patient with a comorbid dHMN that worsened markedly after being treated with copper histidinate. METHODS: We studied in detail the clinical features of the patients and performed a genomic analysis by using TruSight One Expanded Sequencing Panel. Subsequently, we determined the ATP7A and ATP7B expression levels, mitochondrial membrane potential, and redox balance in cultured fibroblasts of Patient 1. RESULTS: We found a novel ATP7A late truncated mutation p.Lys1412AsnfsX15 in the two affected members of this family. The co-occurrence of OHS and dHMN in Patient 1 reveals the variable phenotypic expressivity of the variant. A severe clinical and neurophysiologic worsening was observed in the dHMN of Patient 1 when he was treated with copper replacement therapy, with a subsequent fast recovery after the copper histidinate was withdrawn. Functional studies revealed that the patient had low levels of both ATP7A and ATP7B, the other copper transporter, and high levels of superoxide ion in the mitochondria. CONCLUSIONS: Our findings broaden the clinical spectrum of ATP7A-related disorders and demonstrate that two clinical phenotypes can occur in the same patient. The copper-induced toxicity and low levels of both ATP7A and ATP7B in our patient suggest that copper accumulation in motor neurons is the pathogenic mechanism in ATP7A-related dHMN.

Vascular Ehlers-Danlos Syndrome: Treatment of a Complex Abdominal Wound with Vitamin C and Mesenchymal Stromal Cells.

ABSTRACT: Vascular Ehlers-Danlos syndrome (EDSv) can present with life-threatening surgical complications. The article describes the case of a patient with EDSv who developed total abdominal wound dehiscence and multiple enterocutaneous fistulas. Treatment with IV allogeneic mesenchymal stromal cells (MSCs) and high-dose vitamin C was trialed with success. Near-complete wound healing of the abdominal dehiscence with a 94% reduction in the size of the wound bed occurred. Maturation of the enterocutaneous fistulas also ensued.There is no current consensus on the management of large cutaneous wounds in EDSv. This article discusses the pathophysiology of wound healing with regard to nutrition requirements and growth factors with special reference to collagen deficits in EDSv. A potential therapy with IV vitamin C supplementation and MSCs is proposed following the patient's positive outcome. Medium-dose MSCs and high-dose IV vitamin C may offer significant benefits to complex and problematic wounds.

Biallelic mutations in Tenascin-X cause classical-like Ehlers-Danlos syndrome with slowly progressive muscular weakness.

Tenascin-X, is an extracellular matrix glycoprotein expressed in skin, muscle, tendons, and blood vessels with an anti-adhesive function. Biallelic Tenascin-X mutations cause classical-like Ehlers-Danlos syndrome. We report a 46-year-old woman with slowly progressive weakness of the lower limbs and myalgia from age 28 years. In the past she had Raynaud's phenomenon, multiple sprains and joint dislocations, conjunctival haemorrhages and a colonic perforation during colonoscopy. Neurologic examination showed moderate asymmetric proximal and axial muscular weakness, distal amyotrophy of 4 limbs, moderate skin hyperextensibility, and hypermobility of distal joints of fingers. Whole body Magnetic Resonance Imaging showed symmetric fatty infiltration of thigh and leg muscles, with predominant atrophy of thighs. Next Generation Sequencing revealed two pathogenic TNXB variants, g.32024681C>G, c.7826-1G>C, and g.32016181dup, c.9998dupA, p.(Asn3333Lysfs*35). Western Blot and immunofluorescence studies confirmed a marked Tenascin-X reduction in both patient's serum and muscle. Here we further detail the clinical and genetic spectrum of a patient with classical-like Ehlers-Danlos syndrome and prominent muscle involvement.

Increased augmentation index in patients with Ehlers-Danlos syndrome.

BACKGROUND: Ehlers-Danlos Syndrome (EDS) comprises a heterogeneous group of diseases characterized by joint hypermobility, connective tissue friability, and vascular fragility. Reliable prognostic factors predicting vascular disease progression (e.g. arterial aneurysms, dissections, and ruptures) in EDS patients are still missing. Recently, applanation tonometry derived augmentation index (AIx), an indirect marker of arterial stiffness, has shown to be positively associated with progression of aortic disease in Marfan syndrome. In this study, we assessed aortic AIx in patients with EDS and matched healthy controls. METHODS: We performed noninvasive applanation tonometry in 61 adults with EDS (43 women and 18 men aged 39.3 ± 14.6 years) and 61 age-, gender-, height-, and weight-matched healthy controls. Radial artery pulse waveforms were recorded and analyzed using the SphygmoCor System (AtCor Medical, Sydney, NSW, Australia). Calculated AIx was adjusted to a heart rate of 75/min. Groups were compared and association between AIx and EDS was determined by univariate and multivariate regression analysis. RESULTS: EDS patients were categorized in classical type EDS (34%), hypermobile type EDS (43%), vascular type EDS (5%), or remained unassignable (18%) due to overlapping features. EDS patients showed a significantly increased aortic AIx compared to healthy controls (22.8% ± 10.1 vs 14.8% ± 14.0, p < 0.001). EDS showed a positive association with AIx; independent of age, sex, height, blood pressure, medication, and pack years of smoking. CONCLUSIONS: Patients with EDS showed elevated AIx, indicating increased arterial stiffness when compared to healthy controls. Further investigations are needed in order to assess the prognostic value of increased AIx for cardiovascular outcomes in patients with EDS.

Functional gastrointestinal disorders are increased in joint hypermobility-related disorders with concomitant postural orthostatic tachycardia syndrome.

BACKGROUND: Individuals with hypermobility spectrum disorders/hypermobile Ehlers-Danlos syndrome (HSD/hEDS) frequently fulfill criteria for Rome IV functional gastrointestinal disorders (FGIDs). Postural orthostatic tachycardia syndrome (POTS) is also commonly reported in HSD/hEDS and may impact on co-morbidity with and severity of FGIDs, although this remains to be studied. We determined the impact of concomitant POTS and HSD/hEDS on their association with Rome IV FGIDs. METHODS: With the help of the charity organization Ehlers-Danlos Support UK, an online cross-sectional health survey was completed by individuals with HSD/hEDS. The survey enquired for (a) self-reported doctor diagnosis of POTS, chronic fatigue syndrome, and fibromyalgia, (b) the presence and symptom frequency of Rome IV FGIDs, and (c) anxiety and depression scores. KEY RESULTS: Of 616 subjects with HSD/hEDS, 37.5% reported a doctor diagnosis of POTS. POTS-positive individuals were significantly younger than POTS-negative subjects (37 vs 40 years, P = 0.002), more likely to report chronic fatigue syndrome (44% vs 31%, P < 0.0001), and showed a trend toward increased prevalence of fibromyalgia (44% vs 37%, P = 0.06) and higher depression score (P = 0.07). POTS-positive subjects were also more likely to fulfill criteria for Rome IV FGIDs across various organ domains and experienced both upper and lower gastrointestinal symptoms significantly more frequently. The increased associations for FGIDs and GI symptom frequency remained unchanged in HSD/hEDS subjects with POTS following adjustments for age, chronic fatigue syndrome, fibromyalgia, and depression scores. CONCLUSIONS AND INFERENCES: The high FGID burden in HSD/hEDS is further amplified in the presence of POTS. Future studies should elucidate the mechanism by which POTS arises in HSD/hEDS and is associated with increased GI symptoms.

Clinical features, molecular results, and management of 12 individuals with the rare arthrochalasia Ehlers-Danlos syndrome.

Arthrochalasia Ehlers-Danlos syndrome (aEDS) is a rare autosomal dominant connective tissue disorder that is characterized by congenital bilateral hip dislocations, severe generalized joint hypermobility, recurrent joint (sub)luxations, and skin hyperextensibility. To date, 42 patients with aEDS have been published. We report 12 patients with aEDS from 10 families with 6 unpublished individuals and follow-up data on 6 adult patients. The clinical features are largely comparable with patients reported in the literature. Most (n = 10) patients had variants leading to (partial) loss of exon 6 of the COL1A1 or COL1A2 genes. One patient did not have a previously reported likely pathogenic COL1A1 variant. Data regarding management were retrieved. Hip surgery was performed in 5/12 patients and 3/12 patients underwent spinal surgery. As much as 4/12 patients were wheelchair-bound or unable to walk unaided. Fractures were present in 9/12 individuals with 1 patient requiring bisphosphonate treatment. Echocardiograms were performed in 10 patients and 2 individuals showed an abnormality likely unrelated to aEDS. One patient gave birth to two affected children and went through preterm labor requiring medication but had no additional complications. Of the eight adults in our cohort, the majority entered a career. Our data point toward a genotype-phenotype relationship with individuals with aEDS due to pathogenic COL1A1 variants causing complete or partial loss of exon 6 being more severely affected regarding musculoskeletal features. There is a significant lack of knowledge with regard to management of aEDS, particularly in adulthood. As such, systematic follow-up and multidisciplinary treatment is essential.

The Relationship Between Hypermobile Ehlers-Danlos Syndrome (hEDS), Postural Orthostatic Tachycardia Syndrome (POTS), and Mast Cell Activation Syndrome (MCAS).

In recent years, an association between hypermobile Ehlers-Danlos syndrome (hEDS), mast cell activation syndrome (MCAS), and postural orthostatic tachycardia syndrome (POTS) has garnered attention and patients are increasingly presenting with this triad. However, a real relationship between these entities is unclear due to a lack of scientific validity. We conducted an extensive review of the literature using two different search strategies. A narrower strategy included 88 searches of various combinations of terms for each of the three conditions, yielding 19 unique papers. A broader search included 136 searches of various combinations of terms but included all forms of EDS and yielded 40 unique papers. Of these, only four and nine papers from the narrower and broader search strategies were original research articles. None of these papers resulted from a combination of the search terms for the three conditions. All three clinical entities are controversial in either existence or pathogenesis. MCAS is a poorly defined clinical entity, and many studies do not adhere to the proposed criteria when establishing the diagnosis. Patients previously diagnosed with EDS hypermobility type may not meet the new, stricter criteria for hEDS but may for a less severe hypermobility spectrum disorder (HSD). The pathophysiology of POTS is still unclear. An evidence-based, common pathophysiologic mechanism between any of the two, much less all three conditions, has yet to be described. Our review of the literature shows that current evidence is lacking on the existence of MCAS or hEDS as separate or significant clinical entities. Studies proposing a relationship between the three clinical entities are either biased or based on outdated criteria. The reason behind the purported association of these entities stems from an overlapping pool of vague, subjective symptoms, which is inadequate evidence to conclude that any such relationship exists.

Gleno-humeral abduction measurement in patients with Ehlers-Danlos syndrome.

BACKGROUND: No genetic tests or other investigations are available to establish the definitive diagnosis of Ehlers-Danlos syndrome (EDS). A presumptive diagnosis can be made based on a converging set of findings, including a family history of the disease, the patient's medical history, and the physical findings. The Beighton score is currently the reference standard tool for assessing joint hypermobility, which must be present in at least 5 of 9 tested joints. However, joint hypermobility testing may be challenging, for instance in patients with pain during mobilisation and/or tight hamstring muscles. Furthermore, the Beighton score may be less than 5 in patients with other unequivocal evidence of EDS. The objective of this study was to assess the contribution of gleno-humeral abduction measurement to the diagnosis of EDS. HYPOTHESIS: Gleno-humeral abduction measurement using a standardised method assists in the diagnosis of EDS. METHODS AND MATERIAL: Retrospective case-control study comparing 110 patients with known EDS (cases) to 100 controls. RESULTS: Gleno-humeral abduction was significantly greater in the cases than in the controls, irrespective of age, sex, and Beighton score. Gleno-humeral abduction beyond 90° was 92.5% sensitive and 96.4% specific. Inter-examiner reproducibility of gleno-humeral abduction measurement was excellent. DISCUSSION: Increased gleno-humeral abduction may be sufficient to demonstrate joint hypermobility and to suggest EDS in patients whose personal and family history is consistent with this diagnosis. LEVEL OF EVIDENCE: III, case-control study.

Genome damage in children with classical Ehlers-Danlos syndrome - An in vivo and in vitro study.

Ehlers-Danlos syndrome (EDS) is a heritable connective tissue disorder characterized by skin hyperextensibility, abnormal wound healing, and joint hypermobility with prevalence 1:20 000. Its incidence is probably underestimated due to unknown number of subjects having mild symptoms who may have never been diagnosed through entire life time. Classical EDS is characterized by pathogenic variants of genes encoding type V collagen. The biological effects and health risks of patients with EDS exposure to low doses of ionizing radiation is poorly understood. The aim of this study was to investigate biological effect of low doses of ionizing radiation in children with EDS. Background values of chromosome aberrations in children suffering from classical EDS were determined and compared with control subjects. The in vitro experiment was performed by γ-irradiation of blood lymphocytes from EDS patients and healthy subjects at low doses (0.1, 0.2 and 0.3 Gy). Results show a significant increase level of spontaneous and radiation-induced chromosomal aberrations in children suffering from EDS in comparison with the control subjects (p < 0.05). In conclusion, children with EDS express higher background chromosome aberration frequency and increased radiosensitivity. These findings suggest specific susceptibility of EDS patients and importance of future investigation on risks of diagnostics and therapy which include radiation and genotoxic agents.

Primary muscle involvement in a 15-year-old girl with the recurrent homozygous c.362dupC variant in FKBP14.

Kyphoscoliotic Ehlers-Danlos syndrome associated with FKBP14 (FKBP14-kEDS) is an ultrarare autosomal recessive disorder reported in less than 30 individuals so far. In its original description, emphasis was put on the mild muscle involvement. Further reports confirm that FKBP14-kEDS is distinguishable from primary muscle disorders by the lack of progressive muscle disease. We report a 15-year-old girl with FKBP14-kEDS as a result of the recurrent c.362dupC variant, who also showed severe involvement of the lower limb muscles. She never attained autonomous walking and presented significant lower limb weakness. Lower limb magnetic resonance imaging showed a pattern of multiple muscle involvement. Further musculoskeletal assessment revealed significant bone mass density reduction of the spine, unilateral congenital hip dysplasia, and occipitoatlantoaxial instability. This patient points out the existence of a wider phenotypic spectrum of FKBP14-kEDS to include early onset muscle disease.

Thumb carpometacarpal arthritis in patients with Ehlers-Danlos Syndrome: non-operative and operative experiences.

Ehlers-Danlos Syndrome is a connective tissue disorder that results in joint and generalized tissue hyperlaxity, predisposing patients to early onset arthritis. An institutional database spanning 1999-2016 was reviewed for all patients with symptomatic carpometacarpal arthritis and coexisting Ehlers-Danlos Syndrome, resulting in 14 thumbs amongst nine patients followed clinically for a median of 5.9 years (range 1-15). Patients managed non-operatively demonstrated stable subjective pain and trended towards decreased range of motion over time, whereas patients managed operatively had significant improvements in pain and trended towards increased grip strength. Our findings suggest that patients with Ehlers-Danlos-associated carpometacarpal arthritis can be successfully managed both operatively and non-operatively and that patients with pain refractory to conservative therapy may benefit from relief and increased hand strength following surgical intervention. Level of evidence: IV.

Low- and high-anxious hypermobile Ehlers-Danlos syndrome patients: comparison of psychosocial and health variables.

Despite the frequent co-ocurrence of hypermobile Ehler-Danlos syndrome (hEDS) and pathological anxiety, little is known about the psychosocial and health implications of such comorbidity. Our aim was to explore the association between high levels of anxiety and psychosocial (catastrophizing, kinesiophobia, somatosensory amplification, social support and functioning), health (pain, fatigue, BMI, tobacco/alcohol use, depression, diagnosis delay, general health), and sociodemographic factors in people with hEDS. In this cross-sectional study, 80 hEDS patients were divided into two groups according to self-reported anxiety levels: low and high. Psychosocial, sociodemographic and health variables were compared between the groups. Forty-one participants reported a high level of anxiety (51.2%). No differences were found in the sociodemographic variables between high-anxious and low-anxious patients. The percentage of participants with severe fatigue and high depressive symptomatology was significantly higher in the high-anxious group (80.5 vs 56.4; 26.8 vs 12.8%, respectively). High-anxious hEDS patients also showed significantly higher levels of pain catastrophizing, somatosensory amplification as well as a poorer social functioning and general health. Multivariate analyses showed that somatosensory amplification, pain catastrophizing and poor social functioning are variables that increase the probability of belonging to the high-anxious group. Despite limitations, this first study comparing high-anxious versus low-anxious hEDS patients with respect to health aspects, highlight the importance of considering the psychosocial factors (many susceptible to modification), to improve the adjustment to this chronic condition and provide support to those affected through a biopsychosocial approach.

A multimodal physical therapy approach utilizing the Maitland concept in the management of a patient with cervical and lumbar radiculitis and Ehlers-Danlos syndrome-hypermobility type: A case report.

The purpose of this case report is to present a multimodal approach for patient management using the Maitland concept framework for cervical and lumbar radiculitis with an underlying diagnosis of Ehlers-Danlos Syndrome-Hypermobility Type (EDS-HT). This case presents care guided by evidence, patient values, and rationale for the selected course of physical therapy treatment provided by therapist experience. A 35-year-old female with a 2-year history of worsening lumbar and cervical pain was referred to physical therapy to address these musculoskeletal issues concurrent with diagnostic testing for EDS. A multimodal approach including manual therapy, therapeutic exercise, postural and body mechanics education, and a home exercise program was used. The patient specific functional scale (PSFS) was used to gauge patient's perceived improvements which were demonstrated by increased scores at reevaluation and at discharge. Following the Maitland concept framework, the physical therapist was able to make sound clinical decisions by tracking the logical flow of constant patient assessment. A 10-month course of treatment designed to maximize recovery of function was successful with a chronic history of pain and the EDS-HT diagnosis. The role of education and empowering the patient is shown to be of utmost importance. Optimizing therapeutic outcomes long-term for this patient population requires maintaining a home exercise program, adaptation and modifications of work and lifestyle activities.

Diagnosis of Ehlers-Danlos syndrome after a first shoulder dislocation.

BACKGROUND: Shoulder dislocation is often the first symptom of Ehlers-Danlos syndrome (EDS). Whether it occurs in early-onset EDS is unknown. In most cases, surgical failure leads to the diagnosis. We aimed to determine whether clinical symptoms can signal the presence of EDS at a first dislocation. MATERIALS AND METHODS: In this retrospective study, we analyzed clinical and radiologic data for 27 patients with EDS and shoulder instability and a control population of 40 consecutive non-EDS patients undergoing surgery for an unstable shoulder. Data were collected on gender, age, single or bilateral disease, general hyperlaxity, shoulder hyperlaxity, number of dislocations or subluxations, nontraumatic onset, and pain specificity. Nerve and vascular injuries, joint disorders, and family history were recorded, and radiologic data were reported. RESULTS: Age <14 years, female sex, bilateral disorder, and general hyperlaxity were significantly more frequent in patients with EDS and a first dislocation than in those without EDS. Painless dislocation with pain after dislocation and concomitant nerve injury were more frequent in affected patients, as were hemostasis disorders and a family history of joint hyperlaxity. Bone lesions were not seen on radiographs. Only the hyperlaxity sign (external rotation >85°) did not differ between the groups. CONCLUSION: After a first dislocation in a young girl with global hyperlaxity but not necessarily shoulder hyperlaxity, painless atraumatic dislocation with pain after reduction can suggest EDS.

Biallelic COL3A1 mutations result in a clinical spectrum of specific structural brain anomalies and connective tissue abnormalities.

Vascular Ehlers-Danlos syndrome (type IV) is an autosomal dominant disorder caused by heterozygous variants of COL3A1. We identified biallelic COL3A1 variants in two unrelated families. In a 3-year-old female with developmental delay the nonsense variant c.1282C>T, p.(Arg428*) was detected in combination the c.2057delC, p.(Pro686Leufs*105) frame shift variant. Both compound heterozygous variants were novel. This patient was born with bilateral clubfoot, joint laxity, and dysmorphic facial features. At the age of 2 years she developed an aneurysmal brain hemorrhage. Cerebral MRI showed a peculiar pattern of profound cerebral abnormalities including bilateral frontoparietal polymicrogyria of the cobblestone variant. In the second family, the two affected siblings were homozygous for the missense variant c.145C

Skeletal muscle morphology, protein synthesis, and gene expression in Ehlers-Danlos syndrome.

Patients with Ehlers-Danlos syndrome (EDS) are known to have genetically impaired connective tissue and skeletal muscle symptoms in form of pain, fatigue, and cramps; however earlier studies have not been able to link these symptoms to morphological muscle changes. We obtained skeletal muscle biopsies in patients with classic EDS [cEDS; n = 5 (Denmark)+ 8 (The Netherlands)] and vascular EDS (vEDS; n = 3) and analyzed muscle fiber morphology and content (Western blotting and muscle fiber type/area distributions) and muscle mRNA expression and protein synthesis rate (RT-PCR and stable isotope technique). The cEDS patients did not differ from healthy controls (n = 7-11) with regard to muscle fiber type/area, myosin/α-actin ratio, muscle protein synthesis rate, or mRNA expression. In contrast, the vEDS patients demonstrated higher expression of matrix proteins compared with cEDS patients (fibronectin and MMP-2). The cEDS patients had surprisingly normal muscle morphology and protein synthesis, whereas vEDS patients demonstrated higher mRNA expression for extracellular matrix remodeling in skeletal musculature compared with cEDS patients.NEW & NOTEWORTHY This study is the first of its kind to systematically investigate muscle biopsies from Ehlers-Danlos patients, focusing on muscle structure and function. These patients suffer from severe muscle symptoms, but in our study they show surprisingly normal muscle findings, which points toward indirect muscle symptoms originating from the surrounding connective tissue. These findings have basal physiological importance and implications for future physiotherapeutic treatment options for these patients.