The earliest known description of what we now call Ehlers-Danlos syndrome dates to around 400 BC, when Hippocrates noted the connection between loose joints, fragile skin, and easy bruising. But the syndrome was not recognized as a distinct medical condition until 1901, when the Danish dermatologist Edvard Ehlers presented a case that pulled these scattered observations into a coherent clinical picture. The story between those two dates, and the decades of reclassification that followed, reveals how slowly medicine can move from noticing something unusual to actually understanding it.
From Hippocrates to the Sideshows
Ehlers-Danlos syndrome is one of the oldest documented causes of easy bruising and bleeding, with Hippocrates providing what is generally regarded as the first written account around 400 BC.1PubMed. Ehlers-Danlos syndrome–a historical review For roughly two thousand years after that, individuals with dramatically stretchy skin or hypermobile joints appeared in medical texts only as curiosities. There was no framework to connect the skin laxity, the joint looseness, the fragile blood vessels, and the tendency to bruise at the slightest touch. These were treated as separate oddities rather than pieces of one puzzle.
During the 17th through 19th centuries, people with extreme skin elasticity and joint flexibility were sometimes featured as performers in traveling sideshows. Accounts from that era describe individuals who could stretch their skin several inches from the body or contort their limbs into positions that seemed anatomically impossible. These spectacles attracted medical attention, but the clinical significance was largely missed. Physicians would document cases in isolation, noting “extraordinary laxity of the skin” or “remarkable mobility of the joints” without connecting them to a single underlying disorder.
Ehlers, Danlos, and the Birth of a Diagnosis
The turning point came in 1901, when Edvard Ehlers presented a patient at a dermatology meeting in Paris. Ehlers was the first to argue that the combination of loose joints, hyperextensible skin, and a tendency to bruise easily constituted a recognizable syndrome rather than a collection of unrelated traits.1PubMed. Ehlers-Danlos syndrome–a historical review Seven years later, in 1908, the French dermatologist Henri-Alexandre Danlos built on Ehlers’ work by proposing that skin extensibility and fragility were the cardinal features of the condition.1PubMed. Ehlers-Danlos syndrome–a historical review
Danlos’ contribution was important because it shifted attention from the joints to the skin, giving clinicians a more concrete set of physical findings to look for. At that point, however, neither Ehlers nor Danlos understood the underlying cause. They were describing what they could see and feel on physical examination: skin that stretched too far, joints that bent too much, and tissue that bruised or tore too easily. The biochemical “why” would remain a mystery for another six decades.
The condition did not immediately become known as “Ehlers-Danlos syndrome.” The eponym was suggested in the 1930s by the British physician Frederick Parkes Weber, who reviewed the growing case literature and argued that Ehlers and Danlos deserved joint credit for establishing the syndrome as a clinical entity. The name gradually gained traction, and by mid-century it was the standard label in dermatology and genetics textbooks.
The Collagen Connection
Understanding what actually goes wrong in Ehlers-Danlos syndrome required advances in biochemistry that did not arrive until the 1960s and 1970s. Researchers discovered that collagen, the structural protein that provides tensile strength to skin, tendons, blood vessels, and organs, was produced in multiple distinct types, each encoded by different genes. Once that biochemical landscape came into focus, scientists could begin matching specific EDS symptoms to defects in specific collagen types.
For the classical form of EDS, characterized by very stretchy, velvety skin that bruises easily and heals with unusual scarring, the culprit turned out to be type V collagen. Roughly half of patients with a clinical diagnosis of classical EDS carry mutations in the COL5A1 or COL5A2 genes, which encode the two chains of this collagen type.2Genetics in Medicine. The Ehlers-Danlos syndrome, classic type Subsequent research confirmed that genetic heterogeneity runs deep: causative mutations have been identified not only in COL5A1 and COL5A2 but also in the tenascin X gene and inferred in the COL1A2 gene.3PubMed Central. Null alleles of the COL5A1 gene of type V collagen are a cause of the classical forms of Ehlers-Danlos syndrome (types I and II) In practical terms, this means that even within the “classical” label, different families can have the same symptoms for entirely different genetic reasons.
One study that characterized 40 patients with classical EDS found COL5A1 or COL5A2 mutations in the large majority of those screened, with most mutations leading to the loss of one working copy of the gene rather than the production of a structurally abnormal protein.4PubMed Central. Clinical and molecular characterization of 40 patients with classic Ehlers-Danlos syndrome: identification of 18 COL5A1 and 2 COL5A2 novel mutations That distinction matters because it means the body simply does not make enough type V collagen, rather than making a defective version of it. Both mechanisms lead to fragile connective tissue, but they respond differently at the molecular level.
Vascular EDS and the Recognition of Life-Threatening Subtypes
For much of the 20th century, EDS was viewed primarily as a skin-and-joint condition. That perception changed dramatically with the identification of vascular EDS, which involves mutations in the COL3A1 gene encoding type III collagen.5Genetics in Medicine. COL3A1 haploinsufficiency results in a variety of Ehlers-Danlos syndrome type IV with delayed onset of complications and longer life expectancy Type III collagen is a major component of blood vessel walls, the intestines, and the uterus. When it is defective, the consequences go far beyond bruising.
Vascular EDS carries a high risk of arterial aneurysm, dissection, and spontaneous rupture, as well as bowel perforation and uterine rupture during pregnancy.6PubMed. Diagnosis, natural history, and management in vascular Ehlers-Danlos syndrome A comprehensive study of 142 patients with confirmed vascular EDS in the Netherlands underscored the severity of the condition, documenting the frequency of these catastrophic events across the lifespan.7PubMed Central. Vascular Ehlers-Danlos Syndrome: A Comprehensive Natural History Study in a Dutch National Cohort of 142 Patients The recognition of vascular EDS as a separate, distinctly dangerous subtype was a watershed moment. It moved EDS out of the dermatology textbooks and into cardiology, vascular surgery, and emergency medicine.
People with vascular EDS often do not have the dramatically stretchy skin that defines classical EDS. Their skin tends to be thin and translucent rather than elastic, and their joints are usually less hypermobile than in other subtypes. This means they can be harder to diagnose on physical examination alone, and the first clinical sign is sometimes a medical emergency.
How the Classification System Kept Expanding
As the molecular genetics grew more complex, the classification system had to keep pace. In 1988, an initial Berlin nosology attempted to organize the growing number of EDS variants, but it quickly became outdated. In 1998, a group of experts met in Villefranche, France, and proposed a simplified classification that delineated six subtypes based on clinical features and, where possible, genetic testing. The Villefranche nosology became the diagnostic standard for nearly two decades.8PubMed. The 2017 international classification of the Ehlers-Danlos syndromes
But the Villefranche system could not accommodate the explosion of newly discovered subtypes. By the 2010s, mutations had been found in a growing list of genes, and patients were showing up in clinics with symptoms that did not fit neatly into any of the six Villefranche boxes. In 2017, the International EDS Consortium published a major revision that expanded the classification to 13 recognized subtypes.8PubMed. The 2017 international classification of the Ehlers-Danlos syndromes Each subtype has its own set of major and minor diagnostic criteria, and most now have identified genetic causes. The revision was described as “much needed” given how much the science had moved since 1998.9PubMed Central. Updates in Clinical and Genetics Aspects of Hypermobile Ehlers Danlos Syndrome
The 2017 classification also drew sharper lines around hypermobile EDS, the most common subtype, separating it more clearly from the broader concept of hypermobility spectrum disorders. That distinction has been both clinically useful and a source of frustration for patients who fall in the gray zone between the two categories.
The Hypermobile Subtype and Its Missing Gene
Hypermobile EDS stands out from virtually every other subtype because, as of now, no single causative gene has been identified. For classical EDS, vascular EDS, and most of the rarer subtypes, genetic testing can confirm a diagnosis. For hypermobile EDS, the diagnosis remains purely clinical, based on physical examination findings and a checklist of symptoms. This has been a source of enormous frustration for patients and researchers alike.
A recent genome-wide association study meta-analysis shed some light on why the genetics have been so elusive. Rather than a single gene defect, hypermobile EDS appears to involve a complex genetic architecture with contributions from many regions of the genome. The study prioritized genes that are regulated in nerve tissue, skin, and fibroblasts, and the biological signals converged on neuroimmune signaling and neurodevelopment.10PubMed Central. Complex Genetics and Regulatory Drivers of Hypermobile Ehlers-Danlos Syndrome: Insights from Genome-Wide Association Study Meta-analysis If those findings hold up, they suggest that hypermobile EDS is fundamentally different from the other subtypes at a genetic level. It may not be a single-gene collagen disorder at all, but something more diffuse involving how the nervous and immune systems interact with connective tissue.
This would help explain a longstanding puzzle: why patients with hypermobile EDS so often have symptoms that seem unrelated to stretchy joints, including chronic pain, fatigue, gastrointestinal problems, and autonomic dysfunction. If the condition involves neuroimmune pathways rather than just structural collagen, the wide symptom profile makes more biological sense.
A Long History of Being Dismissed
The gap between when EDS was first described and when it was taken seriously as a multisystem condition is not just a historical curiosity. It has had real consequences for patients, particularly those with the hypermobile subtype. Because many of the symptoms are invisible and the physical examination can appear unremarkable to a physician who is not looking closely, patients have historically been told that their symptoms are psychological.
A retrospective review of 429 patients clinically diagnosed with hypermobile EDS found that an overwhelming majority had experienced some form of diagnostic dismissal. About 88% had been told they were fabricating their symptoms, roughly three-quarters were labeled as attention-seeking, and about two-thirds were misdiagnosed with conversion disorder, a psychiatric diagnosis that implies the symptoms have no physical cause.11PubMed Central. The Incidence of Misdiagnosis in Patients with Ehlers–Danlos Syndrome Overall, more than 94% of patients in the study had been misdiagnosed in at least one of these ways before finally receiving a correct EDS diagnosis.
The gender distribution of EDS adds context to these misdiagnosis rates. A large cohort study in Wales found that women accounted for about 70% of diagnosed EDS cases, and on average, women received their diagnosis over eight years later than men.12PubMed Central. Diagnosed prevalence of Ehlers-Danlos syndrome and hypermobility spectrum disorder in Wales, UK: a national electronic cohort study and case–control comparison That delay reflects both the difficulty of diagnosing a condition with no definitive lab test and the documented tendency for women’s pain complaints to be attributed to psychological causes. The same study found that EDS and related hypermobility diagnoses were associated with significantly higher rates of diagnoses across multiple body systems, including musculoskeletal, mental health, neurological, and gastrointestinal, confirming the multisystem nature of the condition.
How Common Is It, Really?
Estimates of EDS prevalence have shifted dramatically over the decades. Older textbooks often cited a figure of about 1 in 5,000, but that number appears to substantially undercount hypermobile EDS. The Welsh cohort study found a diagnosed point prevalence of about 194 per 100,000, which works out to roughly 1 in 500.12PubMed Central. Diagnosed prevalence of Ehlers-Danlos syndrome and hypermobility spectrum disorder in Wales, UK: a national electronic cohort study and case–control comparison Even that figure represents only diagnosed cases captured in electronic health records. The true prevalence, including undiagnosed individuals, is almost certainly higher.
This dramatic increase in recognized prevalence is not because the condition itself is becoming more common. It reflects growing awareness among clinicians, broader diagnostic criteria, and the fact that patients now have access to information that helps them advocate for evaluation. The rarer subtypes, including vascular, classical, and kyphoscoliotic EDS, remain genuinely uncommon. The prevalence shift is driven almost entirely by the hypermobile subtype.
Paganini and the Question of Historical Diagnoses
Retrodiagnosing historical figures is always speculative, but the violinist Niccolò Paganini is perhaps the most frequently cited candidate for a historical case of EDS. Paganini’s legendary virtuosity, his ability to perform feats on the violin that no other musician could replicate, has long been attributed at least in part to unusual physical characteristics. His extremely long, thin fingers and remarkable flexibility have led medical researchers to suggest that he may have had either EDS or Marfan syndrome, a related connective tissue disorder. One medical analysis concluded that his body build suggests EDS, which could have given him anatomical advantages allowing an extraordinary level of virtuosity.13Revista médica de Chile. Niccolo Paganini: Medical aspects of his life and work
Whether Paganini actually had EDS is unknowable from the historical record. But the case illustrates something important about how the condition intersects with daily life. Hypermobile joints are not purely a liability. For musicians, dancers, gymnasts, and other performers, the extra range of motion can be a genuine advantage, at least early in life. The problems tend to accumulate over time as the unstable joints undergo repeated microtrauma, leading to chronic pain, early arthritis, and frequent dislocations. Many patients with hypermobile EDS describe a trajectory where they were unusually flexible and physically capable as children and teenagers, then progressively more symptomatic as adults. Paganini, who spent his later years in poor health, fits that pattern, though that alone proves nothing.
The broader lesson from Paganini and the sideshow performers of earlier centuries is that EDS has always been visible, in some cases spectacularly so. What took millennia was the medical framework to see the shared biology beneath the surface. Hippocrates noticed the bruising. Ehlers connected the dots. Danlos refined the picture. Molecular genetics explained the mechanism. And the classification system is still catching up to the full complexity of what turns out to be not one syndrome but a family of related disorders, each with its own genetic story and its own clinical profile, unified by the thread of connective tissue that holds the human body together.