Achondroplasia is the most common form of autosomal dominant inherited dwarfism.
The gene was mapped to 4p16.3 and eventually shown to result from distinct mutations in the fibroblast growth factor receptor gene, FGFR3. These substitutions are readily detected by the gain of a Sfc I or Msp I site, respectively. The red arrows indicate restriction fragments obtained by the gain of an Sfc I site in the proband.