Bone
Developmental abnormalities
Achondroplastic dwarfism

Author: Dariusz Borys, M.D. (see Authors page)

Revised: 14 September 2016, last major update June 2012

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Achondroplastic dwarfism[title]
Definition / General
  • Major cause of dwarfism
  • Reduction in chondrocytes at growth plate is due to defect in fibroblastic growth factor receptor 3 gene (FGFR3)
  • FGFR3 inhibits cartilage proliferation, and is constitutively active in these patients
  • Autosomal dominant, but 80% of cases are new mutations
Clinical Features
  • Short proximal extremities, normal trunk, enlarged head (bulging forehead, depression of root of nose)
  • Normal intramembranous bone formation, so bone cortices seem thickened compared to short bone length
  • Normal life, IQ, reproductive status
Micro Description
  • Narrow / disorganized zones of proliferation and hypertrophy in growth plates
  • Chondrocytes in clusters, not columns
  • Base of growth plate has prematurely deposited struts of bone which seal the plate
Additional References