Ehlers-Danlos syndromes

Related Subjects: |Autosomal Dominant |Autosomal Recessive |X Linked Recessive

🌟 Ehlers-Danlos Syndromes (EDS) are a group of inherited connective tissue disorders caused by defects in collagen synthesis and structure. Collagen is the scaffolding protein of skin, joints, vessels, and organs-so when it is faulty, the entire support system of the body is weakened. Common hallmarks include 🤸 joint hypermobility, 🧵 skin hyperextensibility, and 💥 tissue fragility, but the specific presentation varies across subtypes.

📖 About

• A heterogeneous collection of conditions, historically classified as EDS I–X, now recognized as 13 subtypes.
• Overall prevalence ~1 in 5,000 births 👶.
• Most forms are autosomal dominant, though some are autosomal recessive.
• EDS represents a spectrum: some mild with joint laxity, others life-threatening with vascular rupture.

🧬 Aetiology

• Mutations in genes encoding collagen or enzymes that process collagen (e.g., COL5A1, COL3A1, PLOD1).
• Defective collagen biosynthesis → abnormal fibrils → weak connective tissue.
• Faults in post-translational modification (e.g., hydroxylation, cross-linking) impair tensile strength.
• Take-home: study collagen pathways-EDS is essentially “molecular scaffolding gone wrong.”

Gorlin’s sign 👅

🔎 Types of Ehlers-Danlos Syndromes

There are 13 recognized subtypes; the most important exam-relevant ones include:

• Hypermobile EDS (hEDS) 🤸: Most common; marked joint hypermobility, chronic pain, soft/velvety skin. Genetics still not fully defined.
• Classical EDS (cEDS) 🧵: Soft, hyperelastic skin, widened atrophic scars, frequent bruising, joint laxity. Mutations in COL5A1/2.
• Vascular EDS (vEDS) 💔: Most dangerous; fragile arteries, risk of rupture, bowel and uterine rupture. Associated with COL3A1 mutation.
• Kyphoscoliotic EDS (kEDS) 🌀: Severe congenital scoliosis, hypotonia, ocular fragility. Caused by PLOD1 mutations (lysyl hydroxylase deficiency).
• Arthrochalasia EDS (aEDS) 🦴: Severe congenital hip dislocations, extreme joint hypermobility, fragile skin.
• Dermatosparaxis EDS (dEDS) 🩹: Extremely fragile, sagging skin; hernias. Caused by ADAMTS2 mutation.

🩺 Clinical Features

• 🤸 Joint hypermobility: “party trick” joints but prone to sprains/dislocations.
• 🧵 Skin hyperextensibility: Soft, stretchy skin, sometimes with cigarette-paper scars.
• 💥 Tissue fragility: Easy bruising, poor wound healing, atrophic scars.
• 🩹 Musculoskeletal: Chronic pain, fatigue, frequent dislocations, scoliosis.
• 👁️ Ocular: Fragile sclerae → risk of globe rupture (esp. in kEDS).
• ❤️ Cardiovascular: Aortic dilatation, mitral valve prolapse, vascular rupture in vEDS.
• ⚠️ GI: Bowel rupture, hernias.

🧾 Differentials

• Familial Joint Hypermobility (benign, no tissue fragility)
• Marfan’s Syndrome (tall habitus, lens dislocation, fibrillin mutation)
• Larsen’s Syndrome (joint dislocations, craniofacial features)

🧪 Investigations

• Clinical criteria: Beighton score for hypermobility, skin/vascular signs.
• Family history: Key to inheritance pattern.
• Genetic testing: Confirms subtype (esp. vEDS via COL3A1).
• Imaging: Echocardiography for aortic root; MRI for scoliosis/joint pathology.
• Skin biopsy: Can show abnormal collagen fibrils (research/rarely clinical).

Beighton score (0–9) 🦴

The Beighton score is a quick bedside screen for generalised joint hypermobility. It scores 5 manoeuvres (4 are bilateral) to give a total out of 9 - it supports (but does not diagnose) hypermobility spectrum disorders / hEDS. Hypermobility reflects increased connective-tissue laxity (collagen/ECM mechanics), so pair the score with symptoms (pain, sprains, dislocations, dysautonomia features) and skin/family history.

• 1 point each side: Passive dorsiflexion of the 5th finger > 90° (R / L)
• 1 point each side: Thumb touches the forearm (R / L)
• 1 point each side: Elbow hyperextension > 10° (R / L)
• 1 point each side: Knee hyperextension > 10° (R / L)
• 1 point: Palms flat on the floor with knees straight (forward flexion)

• Common cut-offs: ≥ 5/9 adults, ≥ 6/9 children/adolescents, ≥ 4/9 if >50 years (thresholds vary by guideline/context).
• Practical tip: score what you see today (don’t “award for history”), but note pain, prior surgery, and guarding can reduce apparent hypermobility.

💊 Management

• Physiotherapy 🤸: Strengthen periarticular muscles; prevent dislocations.
• Pain management 💊: Paracetamol, NSAIDs, avoid long-term opioids; sometimes neuropathic pain agents.
• Protective strategies 🦾: Braces, taping, mobility aids, avoiding high-impact sports.
• Cardiac surveillance ❤️: Especially in vEDS (yearly echo, vascular imaging).
• Surgery 🩺: High risk due to fragile tissues-reserved for emergencies or severe complications.
• Genetic counseling 🧬: For patients and families.

📌 Clinical Pearls

• Not every hypermobile patient has EDS-distinguish from benign hypermobility.
• vEDS = ⚠️ think “vascular catastrophe” → young person with spontaneous arterial rupture, uterine rupture, or bowel perforation.
• EDS scars often look like “cigarette paper” 🚬-thin, papery, and stretched.
• Always screen for psychological burden-chronic pain & fatigue are disabling.