Bone
Developmental abnormalities
Achondroplastic dwarfism



Topic Completed: 01 June 2012

Revised: 26 December 2018

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Achondroplastic dwarfism[title]
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Cite this page: Borys D Achondroplastic dwarfism. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/boneachondroplastic.html. Accessed January 22nd, 2019.
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
Microscopic (histologic) 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