Growth hormone therapy in achondroplasia.

Achondroplasia is one of the most common causes of severe rhizomelic dwarfism. We have previously reported the growth-promoting effect of growth hormone (GH) in this disorder. In this expanded clinical study, dose dependency and the long-term effect of GH were also investigated. Prepubertal children with achondroplasia (82 males and 63 females) were randomly divided into 2 groups. Patients were treated with 0.5 IU/kg per week or 1.0 IU/kg per week subcutaneous recombinant human GH. Of 75 patients, the mutational analysis of fibroblast growth factor receptor-3 revealed that G1138A was detected in 70 and G1138C was found in 2. GH increased growth rate and height z score in a dose-dependent manner. GH also increased serum insulin-like growth factor (IGF)-I, IGF-binding protein-3 and osteocalcin. No adverse effects were observed in either group. We conclude that GH therapy is a useful method for improvement of severe growth retardation of achondroplasia.