ABSTRACT
Achondroplasia is an autosomal dominant disorder that affects the endochondral growth of bone. It is caused by a point mutation in fibroblast growth factor receptor 3 located on chromosome 4p16.3. Over 80% of the cases result from new mutations in a child born to normal parents. The defective endochondral growth of bone results in rhizomelic dwarfism that has characteristic macrocephaly and hypoplasia of the midface. The disorder is also associated with a delay in achieving milestones such as balanced sitting and walking, which plays a role in the development of the unique achondroplastic spinal deformities.
II. PATHOANATOMY
