Experience in Growth Hormone Therapy in Noonan Syndrome in Japan

Thirty-nine children with Noonan syndrome were treated with growth hormone (GH). Prepubertal height velocity was 4.25 ± 1.31 cm/year (M ± SD) (n=38) before GH therapy, which was increased to 6.23 ± 0.87 cm/year (n=33) in the first year, to 4.92 ± 1.15 cm/year (n=22) in the second year and 4.76 ± 1.25 cm/year (n=13) in the third year. Height velocity SDS for chronological age and height velocity (SDS) for bone age were also improved in the 1st year, but declined progressively during the subsequent years. No adverse effects were observed during GH treatment.These data indicate that GH may be effective in Noonan syndrome, but further studies are required to evaluate the efficacy of long-term GH therapy on adult height and body proportions.