Achondroplasia/Fibroblast Growth Factor 3 Disorder

Achondroplasia/Fibroblast Growth Factor 3 Disorder:
Most common skeletal dysplasia
Autosomal dominant – most cases (80%) are new mutation has low incidence of family history. Most common form of dwarfism. 1 in 30,000- 50,000

Mutation is in the gene coding for fibroblast growth factor receptor 3 (FGFR3)  causes a single amino acid change (glycine replaces arginine) in cell receptor on all prebone cartilage and CNS  inhibition of chondrocyte proliferation in proliferative zone of growth plate

Clinical features:
Facial bossing and midface hypoplasia
Extramities shorter

Lower limb:
Varus deformity.
Tibial torsion- fibula often longer than tibia  varus push on talar

Management:
Body weight management is important