Cover image: Warwick Davis in “Harry Potter and the Goblet of Fire” | Warner Bros | Warwick's dwarfism has been attributed to spondyloepiphyseal dysplasia congenita

Spondyloepiphyseal dysplasia congenita (SED or SDC) is a rare disorder of bone growth that results in dwarfism, characteristic skeletal abnormalities, and occasionally problems with vision and hearing.

• Adult height: 0.9m/35″ to 1.4m/55″

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Aetiology

COL2A1 gene mutation

• Impaired Type II Collagen formation:
  • Required for:
    • Normal development of bones and other connective tissues
    • Found in cartilage and vitreous (eye)

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Clinical features

Short-stature

• Very short trunk and neck and shortened limbs.
• Average-sized hands and feet
• Characterized by a normal spinal column length relative to the femur bone.

Spinal deformities:

• Curvature of the spine (kyphoscoliosis and lordosis)
  • Progresses during childhood and can cause problems with breathing
• Changes in the spinal bones (vertebrae) in the neck may also increase the risk of spinal cord damage.
• Platyspondyly (flattened vertebrae)

Other deformities:

• Coxa vara (hip joint deformity in which the upper leg bones turn inward)
• Clubfoot (inward- and downward-turning foot)
• Decreased joint mobility and arthritis often develop early in life.

Associated conditions:

• Cleft palate
• High myopia (severe nearsightedness)
• Retinal detachment
  
• Mild-to-moderate hearing loss

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Diagnosis

Imaging