The diagnosis of Ehlers-Danlos Syndrome (EDS) is often complex, frequently starting with specialists who treat the disorder’s most noticeable symptoms. Individuals experiencing chronic musculoskeletal pain, joint instability, and extreme flexibility are commonly referred to a rheumatologist for initial evaluation. This symptom overlap places the rheumatologist at an early juncture in the diagnostic process. Understanding the specific responsibilities and limitations of this role helps clarify how an EDS diagnosis is ultimately reached.
The Focus of Rheumatology and Connective Tissue Disorders
Rheumatology focuses on disorders affecting the joints, muscles, and bones, including inflammatory and autoimmune diseases. Patients with Ehlers-Danlos Syndrome frequently present with chronic, widespread musculoskeletal pain, recurrent joint dislocations, and joint hypermobility. These symptoms often prompt a referral to a rheumatologist, whose primary task is differential diagnosis. They work to rule out common autoimmune conditions that can mimic early EDS symptoms.
A rheumatologist investigates conditions like Lupus, Rheumatoid Arthritis, or inflammatory arthritis that cause joint pain and inflammation. Since EDS is a genetic disorder of connective tissue structure, not an inflammatory disease, excluding these possibilities is necessary for an accurate diagnosis. The specialist performs a physical assessment of joint flexibility, often utilizing the Beighton scale. This scale scores hypermobility in nine specific joint movements and provides foundational evidence for diagnosing hypermobile EDS or Hypermobility Spectrum Disorder.
While rheumatologists can manage the pain and instability associated with hypermobility, their core expertise remains inflammatory conditions. Their assessment of joint laxity and the exclusion of other rheumatologic diseases moves the patient forward diagnostically. This initial screening identifies generalized joint hypermobility, a key feature, but does not constitute the full diagnostic confirmation for Ehlers-Danlos Syndrome.
Defining the Ehlers-Danlos Syndromes
Ehlers-Danlos Syndrome represents a group of inherited disorders that compromise the structure and function of connective tissue. These conditions stem from a genetic defect in the synthesis or processing of collagen. Collagen is the most abundant protein, providing strength and elasticity to tissues. The core problem across all subtypes is generalized tissue fragility, leading to symptoms in multiple body systems.
The 2017 international classification recognizes 13 distinct subtypes. Hypermobile EDS (hEDS) is the most common, accounting for an estimated 80% to 95% of cases. Unlike other types, hEDS currently lacks a specific genetic marker, relying entirely on clinical criteria for diagnosis. Other types include Classical EDS (cEDS), involving significant skin hyperextensibility, and Vascular EDS (vEDS), characterized by the fragility of blood vessels and internal organs.
Beyond joint and skin manifestations, the effects of EDS are systemic and diverse, often involving non-musculoskeletal issues. Patients may experience easy bruising, abnormal scarring, chronic fatigue, functional bowel disorders, and autonomic dysfunction like Postural Orthostatic Tachycardia Syndrome (POTS). These widespread symptoms reflect collagen’s role in nearly every organ system, requiring a comprehensive, multidisciplinary approach to diagnosis and management.
The Definitive Diagnostic Path
A rheumatologist is essential for recognizing the signs of EDS, performing the initial differential diagnosis, and managing ongoing symptoms. However, the definitive diagnosis, especially for types requiring genetic confirmation, is typically made by a medical geneticist. The geneticist possesses the specialized experience necessary to differentiate EDS from other heritable connective tissue disorders, such as Marfan syndrome or Loeys-Dietz syndrome.
For most EDS subtypes, including Classical and Vascular EDS, a definitive diagnosis requires molecular genetic testing to identify the specific pathogenic gene variant. For instance, Vascular EDS is confirmed by identifying a mutation in the COL3A1 gene, which codes for type III collagen. Identifying the exact type of EDS is crucial as it informs specific management strategies and allows for accurate family counseling regarding inheritance and risks.
Hypermobile EDS (hEDS) remains unique because, lacking a specific gene marker, the diagnosis relies on a strict set of clinical criteria. This workup involves using the Beighton score to confirm generalized joint hypermobility, assessing for systemic manifestations, and excluding other diagnoses. This exclusion includes reviewing genetic testing results for other EDS types or similar conditions. The rheumatologist acts as a crucial gatekeeper, identifying the clinical suspicion of EDS and managing musculoskeletal symptoms. However, the final, formal confirmation of the specific Ehlers-Danlos Syndrome diagnosis is the responsibility of the medical genetics specialist.