Ehlers-Danlos Syndrome, Hypermobility Type, Is Linked to Chromosome 8p22-8p21.1 in an Extended Belgian Family

Mitochondrial Dysfunction and Its Potential Molecular Interplay in Hypermobile Ehlers-Danlos Syndrome: A Scoping Review Bridging Cellular Energetics and Genetic Pathways

Hypermobile Ehlers-Danlos Syndrome (hEDS) is a hereditary connective tissue disorder characterized by joint hypermobility, skin hyperextensibility, and systemic manifestations such as chronic fatigue, gastrointestinal dysfunction, and neurological symptoms. Unlike other EDS subtypes with known genetic mutations, hEDS lacks definitive markers, suggesting a multifactorial etiology involving both mitochondrial dysfunction and non-mitochondrial pathways. This scoping review, conducted in accordance with the PRISMA-ScR guidelines, highlights mitochondrial dysfunction as a potential unifying mechanism in hEDS pathophysiology. Impaired oxidative phosphorylation (OXPHOS), elevated reactive oxygen species (ROS) levels, and calcium dysregulation disrupt cellular energetics and extracellular matrix (ECM) homeostasis, contributing to the hallmark features of hEDS. We reviewed candidate genes associated with ECM remodeling, signaling pathways, and immune regulation. Protein-protein interaction (PPI) network analyses revealed interconnected pathways linking mitochondrial dysfunction with these candidate genes. Comparative insights from Fabry disease and fragile X premutation carriers underscore shared mechanisms such as RNA toxicity, matrix metalloproteinases (MMP) activation, and ECM degradation. These findings may suggest that mitochondrial dysfunction amplifies systemic manifestations through its interplay with non-mitochondrial molecular pathways. By integrating these perspectives, this review provides a potential framework for understanding hEDS pathogenesis while highlighting latent avenues for future research into its molecular basis. Understanding the potential role of mitochondrial dysfunction in hEDS not only sheds light on its complex molecular etiology but also opens new paths for targeted interventions.

Bridging the Diagnostic Gap for Hypermobile Ehlers-Danlos Syndrome and Hypermobility Spectrum Disorders: Evidence of a Common Extracellular Matrix Fragmentation Pattern in Patient Plasma as a Potential Biomarker

Diagnosing hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD), common overlapping multisystemic conditions featuring symptomatic joint hypermobility, is challenging due to lack of established causes and diagnostic tools. Currently, the 2017 diagnostic criteria for hEDS are used, with non-qualifying cases classified as HSD, although the distinction remains debated. We previously showed extracellular matrix (ECM) disorganization in both hEDS and HSD dermal fibroblasts involving fibronectin (FN), type I collagen (COLLI), and tenascin (TN), with matrix metalloproteinase-generated fragments in conditioned media. Here, we investigated these fragments in patient plasma using Western blotting across diverse cohorts, including patients with hEDS, HSD, classical EDS (cEDS), vascular EDS (vEDS), rheumatoid arthritis (RA), psoriatic arthritis (PsA), and osteoarthritis (OA), and healthy donors, uncovering distinctive patterns. Notably, hEDS/HSD displayed a shared FN and COLLI fragment signature, supporting their classification as a single disorder and prompting reconsideration of the hEDS criteria. Our results hold the promise for the first blood test for diagnosing hEDS/HSD, present insights into the pathomechanisms, and open the door for therapeutic trials focused on restoring ECM homeostasis using an objective marker. Additionally, our findings offer potential biomarkers also for OA, RA, and PsA, advancing diagnostic and therapeutic strategies in these prevalent joint diseases.

Genetic complexity of diagnostically unresolved Ehlers-Danlos syndrome

BACKGROUND

The Ehlers-Danlos syndromes (EDS) are heritable disorders of connective tissue (HDCT), reclassified in the 2017 nosology into 13 subtypes. The genetic basis for hypermobile Ehlers-Danlos syndrome (hEDS) remains unknown.

METHODS

Whole exome sequencing (WES) was undertaken on 174 EDS patients recruited from a national diagnostic service for complex EDS and a specialist clinic for hEDS. Patients had already undergone expert phenotyping, laboratory investigation and gene sequencing, but were without a genetic diagnosis. Filtered WES data were reviewed for genes underlying Mendelian disorders and loci reported in EDS linkage, transcriptome and genome-wide association studies (GWAS). A genetic burden analysis (Minor Allele Frequency (MAF) <0.05) incorporating 248 Avon Longitudinal Study of Parents and Children (ALSPAC) controls sequenced as part of the UK10K study was undertaken using TASER methodology.

RESULTS

Heterozygous pathogenic (P) or likely pathogenic (LP) variants were identified in known EDS and Loeys-Dietz (LDS) genes. Multiple variants of uncertain significance where segregation and functional analysis may enable reclassification were found in genes associated with EDS, LDS, heritable thoracic aortic disease (HTAD), Mendelian disorders with EDS symptomatology and syndromes with EDS-like features. Genetic burden analysis revealed a number of novel loci, although none reached the threshold for genome-wide significance. Variants with biological plausibility were found in genes and pathways not currently associated with EDS or HTAD.

CONCLUSIONS

We demonstrate the clinical utility of large panel-based sequencing and WES for patients with complex EDS in distinguishing rare EDS subtypes, LDS and related syndromes. Although many of the P and LP variants reported in this cohort would be identified with current panel testing, they were not at the time of this study, highlighting the use of extended panels and WES as a clinical tool for complex EDS. Our results are consistent with the complex genetic architecture of EDS and suggest a number of novel hEDS and HTAD candidate genes and pathways.

Sensory Profiling in Classical Ehlers-Danlos Syndrome: A Case-Control Study Revealing Pain Characteristics, Somatosensory Changes, and Impaired Pain Modulation

Pain is one of the most important yet poorly understood complaints in heritable connective tissue disorders (HCTDs) caused by monogenic defects in extracellular matrix molecules. This is particularly the case for the Ehlers-Danlos syndrome (EDS), paradigm collagen-related disorders. This study aimed to identify the pain signature and somatosensory characteristics in the rare classical type of EDS (cEDS) caused by defects in type V or rarely type I collagen. We used static and dynamic quantitative sensory testing and validated questionnaires in 19 individuals with cEDS and 19 matched controls. Individuals with cEDS reported clinically relevant pain/discomfort (Visual Analogue Scale ≥5/10 in 32% for average pain intensity the past month) and worse health-related quality of life. An altered somatosensory profile was found in the cEDS group with higher (P = .04) detection thresholds for vibration stimuli at the lower limb, indicating hypoesthesia, reduced thermal sensitivity with more (P < .001) paradoxical thermal sensations (PTSs), and hyperalgesia with lower pain thresholds to mechanical (P < .001) stimuli at both the upper and lower limbs and cold (P = .005) stimulation at the lower limb. Using a parallel conditioned pain modulation paradigm, the cEDS group showed significantly smaller antinociceptive responses (P-value .005-.046) suggestive of impaired endogenous pain modulation. In conclusion, individuals with cEDS report chronic pain and worse health-related quality of life and present altered somatosensory perception. This study is the first to systematically investigate pain and somatosensory characteristics in a genetically defined HCTD and provides interesting insights into the possible role of the ECM in the development and persistence of pain. PERSPECTIVE: Chronic pain compromises the quality of life in individuals with cEDS. Moreover, an altered somatosensory perception was found in the cEDS group with hypoesthesia for vibration stimuli, more PTSs, hyperalgesia for pressure stimuli, and impaired pain modulation.

Folate-dependent hypermobility syndrome: A proposed mechanism and diagnosis

Hypermobility involves excessive flexibility and systemic manifestations of connective tissue fragility. We propose a folate-dependent hypermobility syndrome model based on clinical observations, and through a review of existing literature, we raise the possibility that hypermobility presentation may be dependent on folate status. In our model, decreased methylenetetrahydrofolate reductase (MTHFR) activity disrupts the regulation of the ECM-specific proteinase matrix metalloproteinase 2 (MMP-2), leading to high levels of MMP-2 and elevated MMP-2-mediated cleavage of the proteoglycan decorin. Cleavage of decorin leads ultimately to extracellular matrix (ECM) disorganization and increased fibrosis. This review aims to describe relationships between folate metabolism and key proteins in the ECM that can further explain the signs and symptoms associated with hypermobility, along with possible treatment with 5-methyltetrahydrofolate supplementation.

Outcomes and Complications in Patients With Hypermobile Ehlers-Danlos Syndrome Who Have Undergone Laser In Situ Keratomileusis Surgery

PURPOSE

The purpose of this study was to determine the safety and outcomes of myopic laser in situ keratomileusis (LASIK) in patients who were secondarily diagnosed with hypermobile Ehlers-Danlos syndrome (EDS).

METHODS

We conducted a case series study on patients with hypermobile EDS who underwent myopic LASIK surgery. Visual acuity, manifest refraction, a full dilated eye examination, biometry measurements, and Scheimpflug imaging were performed in the Wilmer outpatient clinic.

RESULTS

There were 24 eyes of 12 patients included in this study. All participants were White women with a mean age of 46.58 years (SD 8.91 years). Participants were seen at an average of 13.83 years (SD 4.3 years, range 6-21 years) after undergoing LASIK. None of the patients in the series had a diagnosis of hypermobile EDS before LASIK surgery. Overall, 92% of patients were happy they got LASIK. The uncorrected distance visual acuity was 20/20 or better in 68% of eyes, and the best-corrected visual acuity was 20/20 or better in 92% of eyes. Manifest refraction was within 1 diopter of plano in 79% of patients. Dry eye symptoms were present in 83% of patients, and 46% of eyes had either punctate epithelial erosions or decreased tear break-up time. One of the 12 patients developed corneal ectasia in both eyes.

CONCLUSIONS

Patients with hypermobile EDS are generally satisfied with myopic LASIK correction, with good visual acuity outcomes and low rates of myopic regression. However, the risk of corneal ectasia may prevent laser vision correction from being a viable treatment option in these patients. Further studies are needed to make a definitive recommendation.

Polymorphic Variants of the <i>ADAMTS5</i> Gene as New Markers of Joint Hypermobility

Joint hypermobility (JH) is a common phenotype that can be both an independent clinical syndrome and a manifestation of connective tissue diseases. The pathogenesis of JH is not well understood. JH may be a predisposing factor in the development of musculoskeletal system pathology, so it is necessary to identify its molecular markers to prevent the formation of associated disorders.Objective: to search for associations of five polymorphic variants of the ADAMTS5 gene with JH and connective tissue dysplasia (CTD).Material and methods. A one-stage screening study of young people (n=181, mean age 21.86±0.22 years) was performed. We searched for associations of polymorphic variants of the rs226794, rs9978597, rs2830585, rs229077, rs229069 loci of the ADAMTS5 gene with JH, undifferentiated CTD, and their combinations. JH was determined by the Beighton scale, CTD – by a quantitative method. The study of polymorphic variants was carried out using real-time polymerase chain reaction. To compare qualitative features, Fisher's exact test with Yates’s correction for 2×2 contingency tables was used. The strength of associations was assessed using the odds ratio (OR), differences were considered significant at p<0.05, the correction for multiple comparisons was performed using the Benjamini–Hochberg method (false discovery rate, FDR).Results and discussion. JH was detected in 128 (70.7%), signs of CTD – in 129 (71.3%) patients, including 115 (63.5%) patients in combination with JH. We found associations of the T allele and the TT genotype of the rs9978597 locus with the presence of JH (OR 5.00 and 7.81, respectively), CTD (OR 3.13 and 3.96), or their combinations (OR 6.33 and 10.23). An association of the GG genotype of the rs226794 locus with isolated JH was also found (OR 3.87).Conclusion. The GG genotype of the rs226794 locus of the ADAMTS5 gene is a marker of isolated JH, the T allele of the rs9978597 locus is a marker of both isolated JH and CTD, and their combination.

Genomic Characterization by Whole-Exome Sequencing of Hypermobility Spectrum Disorder

No genetic basis is currently established that differentiates hypermobility spectrum disorders (HSD) from hypermobile Ehlers–Danlos syndrome (hEDS). Diagnosis is entirely based on clinical parameters with high overlap, leading to frequent misdiagnosis of these two phenotypes. This study presents a landscape of DNA mutations through whole-exome sequencing of patients clinically diagnosed with generalized HSD. In this study, three genes (MUC3A, RHBG, and ZNF717) were mutated in all five patients evaluated. The functional enrichment analysis on all 1162 mutated genes identified the extracellular matrix (ECM) structural constituent as the primary overrepresented molecular function. Ingenuity pathway analysis identified relevant bio-functions, such as the organization of ECM and hereditary connective tissue disorders. A comparison with the matrisome revealed 55 genes and highlighted MUC16 and FREM2. We also contrasted the list of mutated genes with those from a transcriptomic analysis on data from Gene Expression Omnibus, with only 0.5% of the genes at the intersection of both approaches supporting the hypothesis of two different diseases that inevitably share a common genetic background but are not the same. Potential biomarkers for HSD include the five genes presented. We conclude the study by describing five potential biomarkers and by highlighting the importance of genetic/genomic approaches that, combined with clinical data, may result in an accurate diagnosis and better treatment.

Pain in the Ehlers-Danlos syndromes: Mechanisms, models, and challenges

Chronic pain is one of the most common, yet poorly studied, complaints in people suffering from Ehlers-Danlos syndromes (EDS). This heterogeneous group of heritable connective tissue disorders is typically characterized by skin hyperextensibility, joint hypermobility, and generalized connective tissue fragility. Most EDS types are caused by genetic defects that affect connective tissue biosynthesis, thereby compromising collagen biosynthesis or fibrillogenesis and resulting in a disorganized extracellular matrix. Even though chronic pain is a major source of disability, functional impairment, and psychosocial suffering in EDS, currently used analgesics and other treatment strategies provide inadequate pain relief and thus represents an important unmet medical need. An important contributor to this is the lack of knowledge about the underlying mechanisms. In this narrative review, we summarize the current understanding of pain and the associated mechanisms in EDS based on clinical studies focusing on questionnaires and experimental pain testing as well as studies in animal models of EDS. In addition, we highlight the challenges, gaps, and opportunities in EDS-pain research.

Biomarkers for Ehlers-Danlos Syndromes: There Is a Role?

Ehlers-Danlos syndromes (EDS) are an inherited heterogeneous group of connective tissue disorders characterized by an abnormal collagen synthesis affecting skin, ligaments, joints, blood vessels, and other organs. It is one of the oldest known causes of bruising and bleeding, and it was described first by Hippocrates in 400 BC. In the last years, multiple gene variants involved in the pathogenesis of specific EDS subtypes have been identified; moreover, new clinical diagnostic criteria have been established. New classification models have also been studied in order to differentiate overlapping conditions. Moreover, EDS shares many characteristics with other similar disorders. Although distinguishing between these seemingly identical conditions is difficult, it is essential in ensuring proper patient care. Currently, there are many genetic and molecular studies underway to clarify the etiology of some variants of EDS. However, the genetic basis of the hypermobile type of EDS (hEDS) is still unknown. In this review, we focused on the study of two of the most common forms of EDS-classic and hypermobile-by trying to identify possible biomarkers that could be of great help to confirm patients' diagnosis and their follow up.

Hypermobile Ehlers-Danlos syndrome: A review and a critical appraisal of published genetic research to date

The Ehlers-Danlos syndromes (EDS) are a collection of rare hereditary connective tissue disorders with heterogeneous phenotypes, usually diagnosed following clinical examination and confirmatory genetic testing. Diagnosis of the commonest subtype, hypermobile Ehlers-Danlos Syndrome (hEDS), relies solely on a clinical diagnosis since its molecular aetiology remains unknown. We performed an up-to-date literature search and selected 11 out of 304 publications according to a set of established criteria. Studies reporting variants affecting collagen proteins were found to be hindered by cohort misclassification and subsequent lack of reproducibility of these genetic findings. The role of the described variants affecting Tenascin-X and LZTS1 is yet to be demonstrated in the majority of hEDS cases, while the functional implication of associated signaling pathways and genes requires further elucidation. The available literature on the genetics of hEDS is scant, dispersed and conflicting due to out-dated nosology terminology. Recent literature has suggested the role of several promising candidate mechanisms which may be linked to the underlying molecular aetiology. Knowledge of the molecular genetic basis of hEDS is expected to increase in the near future through the mainstream use of high-throughput sequencing combined with the updated classification of EDS, and the upcoming Hypermobile Ehlers-Danlos Genetic Evaluation (HEDGE) study.

Hypermobile Disorders and Their Effects on the Hip Joint

Hypermobility, or joint hyperlaxity, can result from inherited connective tissue disorders or from micro- or macrotrauma to a joint. The supraphysiologic motion of the hip joint results in capsuloligamentous damage, and these patients have a propensity to develop femoroacetabular impingement syndrome (FAIS) and labral injury. In this review, the recent literature evaluating the definitions, history, incidence, genetics, and histology of hypermobile disorders is investigated. We then review the clinical evaluation, natural history, and resulting instability for patients presenting with a hypermobile hip. Lastly, treatment options and outcomes will be highlighted.

Hypermobile Ehlers-Danlos syndromes: Complex phenotypes, challenging diagnoses, and poorly understood causes

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 13 subtypes. The initial genetic findings on EDS were related to alterations in fibrillar collagen, but the elucidation of the molecular basis of many of the subtypes revealed several genes not involved in collagen biosynthesis or structure. However, the genetic basis of the hypermobile type of EDS (hEDS) is still unknown. 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 comorbid conditions. Variability in the spectrum and severity of symptoms and progression of patient phenotype likely depend on age, gender, lifestyle, and expression domains of the EDS genes during development and postnatal life. In this review, we summarize the current molecular, genetic, epidemiologic, and pathogenetic findings related to EDS with a focus on the hypermobile type.

Pelvic Girdle Pain, Hypermobility Spectrum Disorder and Hypermobility-Type Ehlers-Danlos Syndrome: A Narrative Literature Review

Pelvic girdle pain (PGP) refers specifically to musculoskeletal pain localised to the pelvic ring and can be present at its anterior and/or posterior aspects. Causes such as trauma, infection and pregnancy have been well-established, while patients with hypermobile joints are at greater risk of developing PGP. Research exploring this association is limited and of varying quality. In the present study we report on the incidence, pathophysiology, diagnostic and treatment modalities for PGP in patients suffering from Hypermobility Spectrum Disorder (HSD) and Hypermobility-Type Ehlers-Danlos Syndrome (hEDS). Recommendations are made for clinical practice by elaborating on screening, diagnosis and management of such patients to provide a holistic approach to their care. It appears that this cohort of patients are at greater risk particularly of mental health issues. Moreover over, they may require a multidisciplinary approach for their management. Ongoing research is still required to expand our understanding of the relationship between PGP, HSD and hEDS by appropriately diagnosing patients using the latest updated terminologies and by conducting randomised control trials to compare outcomes of interventions using standardised patient reported outcome measures.

The effects of joint hypermobility syndrome on the kinematics and kinetics of the vertical jump test

PURPOSE

Biomechanical impairments are not apparent during walking in people with Joint Hypermobility Syndrome (JHS). This research explored biomechanical alterations during a higher intensity task, vertical jumping.

MATERIALS AND METHODS

This cross-sectional study compared a JHS group (n = 29) to a healthy control group (n = 30). Joint kinematics and kinetics were recorded using a Qualisys motion capture system synchronized with a Kistler platform. Independent sample t-tests and standardised mean differences (SMD) were used for statistical analysis.

RESULTS

No significant statistical or clinical differences were found between groups in joint kinematics and jump height (p ≥ 0.01). Sagittal hip and knee peak power generation were statistically lower in the JHS group during the compression phase (p ≤ 0.01), but not clinically relevant (SMD < 0.5). Clinically relevant reductions were found in the JHS group knee and ankle peak moments during the compression phase, and hip and knee peak power generation during the push phase (SMD ≥ 0.5), although these were not statistically significant (p ≥ 0.01).

CONCLUSION

The JHS group achieved a similar jump height but with some biomechanical alterations. Further understanding of the joint biomechanical behavior could help to optimize management strategies for JHS, potentially focusing on neuromuscular control and strength/power training.

The role of chromosomal microarray analysis among fetuses with normal karyotype and single system anomaly or nonspecific sonographic findings

INTRODUCTION

Chromosomal microarray analysis is recommended as the first-tier test for the evaluation of fetuses with structural anomalies. This study aims to investigate the incremental diagnostic yield of chromosomal microarray over conventional karyotyping analysis in fetuses with anomalies restricted to one anatomic system and those with nonspecific anomalies detected by sonography.

MATERIAL AND METHODS

This is a retrospective cohort analysis of 749 fetuses undergoing prenatal diagnosis for abnormal ultrasound findings isolated to one anatomic system and normal karyotype, utilizing chromosomal microarray. Overall, 495 (66%) fetuses had anomalies confined to one anatomic system and 254 (34%) had other nonspecific anomalies including increased nuchal translucency (≥3.5 mm), cystic hygroma, intrauterine growth restriction and hydrops fetalis.

RESULTS

Fetuses with ultrasound anomalies restricted to one anatomic system had a 3.0% risk of carrying a pathogenic copy number variant; the risk varied dependent on the anatomic system affected. Fetuses with confined anomalies of the cardiac system had the highest diagnostic yield at 4.6%, but there were none in the urogenital system. Fetuses with nonspecific ultrasound anomalies had the highest diagnostic yield in fetuses with an intrauterine growth restriction at 5.9%. Overall, fetuses with a nonspecific ultrasound anomaly were affected with pathogenic copy number variants in 1.6% in the cases.

CONCLUSIONS

The diagnostic yield of chromosomal microarray in fetuses with normal karyotype and ultrasound abnormality confined to a single anatomic system was highest if it involved cardiac defects or intrauterine growth restriction. This diagnostic yield ranges from 0% to 4.6% depending on the anatomic system involved. Chromosomal microarray has considerable diagnostic value in these pregnancies.

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.

Cellular and Molecular Mechanisms in the Pathogenesis of Classical, Vascular, and Hypermobile Ehlers‒Danlos Syndromes

The Ehlers‒Danlos syndromes (EDS) constitute a heterogenous group of connective tissue disorders characterized by joint hypermobility, skin abnormalities, and vascular fragility. The latest nosology recognizes 13 types caused by pathogenic variants in genes encoding collagens and other molecules involved in collagen processing and extracellular matrix (ECM) biology. Classical (cEDS), vascular (vEDS), and hypermobile (hEDS) EDS are the most frequent types. cEDS and vEDS are caused respectively by defects in collagen V and collagen III, whereas the molecular basis of hEDS is unknown. For these disorders, the molecular pathology remains poorly studied. Herein, we review, expand, and compare our previous transcriptome and protein studies on dermal fibroblasts from cEDS, vEDS, and hEDS patients, offering insights and perspectives in their molecular mechanisms. These cells, though sharing a pathological ECM remodeling, show differences in the underlying pathomechanisms. In cEDS and vEDS fibroblasts, key processes such as collagen biosynthesis/processing, protein folding quality control, endoplasmic reticulum homeostasis, autophagy, and wound healing are perturbed. In hEDS cells, gene expression changes related to cell-matrix interactions, inflammatory/pain responses, and acquisition of an in vitro pro-inflammatory myofibroblast-like phenotype may contribute to the complex pathogenesis of the disorder. Finally, emerging findings from miRNA profiling of hEDS fibroblasts are discussed to add some novel biological aspects about hEDS etiopathogenesis.

Bilateral Medial and Lateral Patellofemoral Ligament Reconstruction in a Patient with Hypermobility Type Ehlers-Danlos Syndrome: A Case Report

CASE

Medial patellar instability (MPI) is a known sequela of previous lateral retinacular release. Literature on surgical intervention is scarce. We present a case of a 35-year-old woman with hypermobility type Ehlers-Danlos syndrome, with bilateral iatrogenic MPI (IMPI) and lateral patellar instability. This condition led to a marked decrease in quality of life, 10/10 persistent pain, and frequent dislocation events. She was successfully treated surgically, and at 2 years had 0/10 pain and no further dislocations.

CONCLUSIONS

Our technique for medial and lateral patellofemoral ligament reconstruction is a viable intervention for patients with IMPI, even in the setting of underlying collagen disorder.

Updates in Clinical and Genetics Aspects of Hypermobile Ehlers Danlos Syndrome

Efforts on recognition, diagnosis, and management of the presumed, most common connective tissue disorder hypermobile Ehlers-Danlos syndrome have been an ongoing challenge, even decades after the description of this condition. A recent international consortium proposed a revised Ehlers-Danlos syndrome classification, an update much needed since Villefranche nosology, in 1998. Hypermobile Ehlers-Danlos syndrome is the only subtype in these groups of syndromes with no known genetic cause(s). This effort brought significant attention to this often underappreciated condition. This review provides an update of the clinical and genetic aspects of hypermobile Ehlers-Danlos syndrome for clinicians and researchers.

[Ehlers-Danlos syndromes]

Ehlers-Danlos syndromes (EDS) are a heterogeneous group of inheritable connective tissue disorders characterized by skin hyperextensibility, joint hypermobility and cutaneous fragility with delayed wound healing. Over and above these common features, they differ in the presence or absence of various organ and tissue abnormalities, and differences in genetic causal mechanisms and degree of severity. They are complex and multisystem diseases, with the majority being highly disabling because of major joint problems and neurosensory deficiencies, and in some cases, they may be life-threatening due to associated complications, especially vascular disorders. In 1997, the Villefranche classification defined 6 subtypes of EDS. However, many other new variants have been described over the last years. The "historical" EDS were characterized by abnormalities in fibrillar collagen protein synthesis. More recently, disorders of synthesis and organization of the extracellular matrix have been shown to be responsible for other types of EDS. Thus, many EDS are in fact metabolic diseases related to enzymatic defects. While there is no curative treatment for any type of EDS, early diagnosis is of utmost importance in order to optimize the symptomatic management of patients and to prevent avoidable complications. Patients must be treated and monitored by multidisciplinary teams in highly specialized reference centers. In this article, we present the current state of knowledge on these diseases that continue to be elucidated thanks to new molecular genetic techniques.

Transcriptome-Wide Expression Profiling in Skin Fibroblasts of Patients with Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome Hypermobility Type

Joint hypermobility syndrome/Ehlers–Danlos syndrome hypermobility type (JHS/EDS-HT), is likely the most common systemic heritable connective tissue disorder, and is mostly recognized by generalized joint hypermobility, joint instability complications, minor skin changes and a wide range of satellite features. JHS/EDS-HT is considered an autosomal dominant trait but is still without a defined molecular basis. The absence of (a) causative gene(s) for JHS/EDS-HT is likely attributable to marked genetic heterogeneity and/or interaction of multiple loci. In order to help in deciphering such a complex molecular background, we carried out a comprehensive immunofluorescence analysis and gene expression profiling in cultured skin fibroblasts from five women affected with JHS/EDS-HT. Protein study revealed disarray of several matrix structural components such as fibrillins, tenascins, elastin, collagens, fibronectin, and their integrin receptors. Transcriptome analysis indicated perturbation of different signaling cascades that are required for homeostatic regulation either during development or in adult tissues as well as altered expression of several genes involved in maintenance of extracellular matrix architecture and homeostasis (e.g., SPON2, TGM2, MMP16, GPC4, SULF1), cell-cell adhesion (e.g., CDH2, CHD10, PCDH9, CLDN11, FLG, DSP), immune/inflammatory/pain responses (e.g., CFD, AQP9, COLEC12, KCNQ5, PRLR), and essential for redox balance (e.g., ADH1C, AKR1C2, AKR1C3, MAOB, GSTM5). Our findings provide a picture of the gene expression profile and dysregulated pathways in JHS/EDS-HT skin fibroblasts that correlate well with the systemic phenotype of the patients.