🦴 Chapter 736 · Disorders Involving Cartilage Matrix Proteins

Nelson Textbook of Pediatrics 22nd Edition | Type II Collagenopathies (COL2A1): spectrum from lethal (achondrogenesis type II, hypochondrogenesis) to severe (SED congenita, Kniest) to mild (Stickler, premature osteoarthritis). Type XI Collagen (COL11A1, COL11A2): Stickler syndrome (non-ocular), Marshall syndrome. COMP: pseudoachondroplasia (severe short-limbed dwarfism, normal facies), multiple epiphyseal dysplasia (MED). Schmid metaphyseal dysplasia (COL10A1): mild short stature, coxa vara, bowing. Aggrecan mutations: SED-like, familial osteochondritis dissecans.

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📋 30 Clinical Scenarios — Cartilage Matrix Protein Disorders

📇 High‑Yield Review Cards

🩺 Clinical Recognition: Cartilage Matrix Protein Disorders

Select a presentation to review diagnostic clues and management per Nelson Ch 736.

📋 Stepwise Management of Cartilage Matrix Protein Disorders

🔑 Key Principles — Nelson Chapter 736
• COL2A1 disorders: SED congenita → short trunk, odontoid hypoplasia (cervical instability), myopia, retinal detachment. Kniest → dumbbell bones, cleft palate. Stickler → Pierre Robin, myopia, hearing loss.
• Pseudoachondroplasia (COMP): Normal facies and intelligence, severe short-limbed dwarfism (adult height 105-128 cm), joint laxity, early osteoarthritis.
• Multiple epiphyseal dysplasia (COMP, COL9, MATN3): Mild short stature, waddling gait, early-onset osteoarthritis (hips, knees). Double-layered patella (pathognomonic).
• Schmid metaphyseal dysplasia (COL10A1): Mild short stature, coxa vara, bowing of legs, metaphyseal flaring on X-ray.
• Management: Cervical spine fusion for instability, joint replacement for osteoarthritis, ophthalmology (retinal detachment), audiology.

    ⚡ Reflex Prompts — Clinical Decisions

    📖 Summary: Cartilage Matrix Protein Disorders (Nelson 736)