Molecular defects in achondroplasia and the effects of growth hormone treatment.

Achondroplasia is a common skeletal dysplasia with severe growth retardation. Recently, mutations in the fibroblast growth factor receptor 3 (FGFR3) were identified in patients with achondroplasia. In the present study, 70 of 75 Japanese patients with achondroplasia were found to have a G1138A mutation in FGFR3, and two patients had a G1138C mutation. Growth hormone therapy was given to 145 patients with achondroplasia. Significant dose-dependent effects on skeletal growth were obtained, with no long-term adverse effects.