Ehlers-Danlos Syndromes (EDS)

Overview

• Definition: Ehlers-Danlos syndromes (EDS) are a group of 13 heritable connective tissue disorders.
• Causes: Genetic changes affecting connective tissue.
• Common Features: Joint hypermobility, skin hyperextensibility, and tissue fragility.

Key Characteristics

Joint Hypermobility

• Definition: Greater than usual range of motion in joints.
• Impact: Can lead to instability, subluxations, dislocations, sprains, and pain.
• Prevalence in EDS: Common across most types, but not all EDS types involve joint hypermobility.

Skin Hyperextensibility

• Definition: Skin stretches beyond normal range.
• Measurement: Greater than 1.5 cm considered hyperextensible.
• Features: Unusual skin texture, fragility, delayed healing, and abnormal scarring.

Tissue Fragility

• Definition: Increased vulnerability to damage.
• Symptoms: Easy bruising, poor wound healing, severe fragility of organs and other structures.

Types of EDS

Hypermobile EDS (hEDS)

• Prevalence: Most common (1 in 3,100-5,000).
• Genetic Basis: Unknown.
• Inheritance: Autosomal Dominant.
• Distinguishing Features: Generalized joint hypermobility, joint instability, chronic pain.

Classical EDS (cEDS)

• Prevalence: 1 in 20,000-40,000.
• Genes/Proteins: COL5A1, COL5A2, COL1A1 (Type V and I collagen).
• Inheritance: Autosomal Dominant.
• Distinguishing Features: Skin fragility, atrophic scarring, stretchy skin.

Vascular EDS (vEDS)

• Prevalence: 1 in 100,000-200,000.
• Genes/Proteins: COL3A1, COL1A1 (Type III and I collagen).
• Inheritance: Autosomal Dominant.
• Distinguishing Features: Arterial fragility, organ fragility, pneumothorax.

Other Types

• Periodontal EDS (pEDS): Rare, severe gum disease.
• Kyphoscoliotic EDS (kEDS): Congenital kyphoscoliosis.
• Spondylodysplastic EDS (spEDS): Short stature, craniofacial features.
• Brittle Cornea Syndrome (BCS): Severe corneal issues.
• Arthrochalasia EDS (aEDS): Severe joint hypermobility.
• Musculocontractural EDS (mcEDS): Multiple contractures.
• Classical-like EDS (clEDS): Skin features without scarring.
• Dermatosparaxis EDS (dEDS): Extreme skin fragility.
• Myopathic EDS (mEDS): Hypotonia, joint contractures.
• Cardiac-valvular EDS (cvEDS): Heart valve insufficiency.

Diagnosis and Management

• Diagnosis: Based on clinical criteria; genetic testing confirms most types except hEDS.
• Management: Symptom-based, requiring multidisciplinary care teams.

Inheritance

• Patterns: Autosomal dominant or recessive.
• De Novo Mutations: Possible first occurrence in a family.

Historical Context

• Naming: Named after Dr. Ehlers and Dr. Danlos.
• Classification Evolution: From 11 types (1986) to 13 types (2017). HSD introduced in 2017 classification.

Prevalence and Research

• Prevalence: hEDS most common; other types are ultra-rare.
• Research Focus: Genetic causes, management strategies, and international classification updates.