Growth

Achondroplasia

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Achondroplasia, Congenital Dwarfism

  • Epidemiology
  1. Incidence: 1 in 40,000 births
  2. Most common etiology for short-limb syndrome
  • Pathophysiology
  1. Hereditary (Autosomal Dominant)
  2. Disease of cartilage and endochondral bone growth
  • Signs
  1. Facial features
    1. Recessed Nasal Bridge
    2. Large brachiocephalic head (prominent forehead)
    3. Prominent jaw
  2. Trunk and spine features
    1. Normal trunk
    2. Dorsal kyphosis
    3. Backward-tilting Sacrum
    4. Slight Abdominal Distention
  3. Limb features
    1. Rhizomelic limb shortening
    2. Short muscular limbs
    3. Stubby hands with thick fingers
  • Associated conditions
  1. Eustachian Tube Dysfunction
  2. Sleep Apnea
  3. Hydrocephalus (infants)
  4. Lumbosacral spinal stenosis
  • Radiology
  • Skeletal XRay
  1. Short bowed wide bones with expanded ends
  2. Increased bone density
  3. Characteristic cupping of metaphases
  4. Incomplete glenoid fossa and acetabulum
  5. Wide joint spaces
  • Course
  1. Adult height: 4 feet
  2. Normal intelligence development
  • References
  1. Hall (1995) Pediatrics 95:443-451 [PubMed]