The growth characteristics of patients with Noonan syndrome, and first 3 years results of GH treatment: A Nationwide multicenter study.

Abstract Noonan syndrome (NS) is a multisystem disorders and short stature is a most striking manifestation. The optimal GH treatment for NS is still controversial. In this study, we aimed to evaluate the growth characteristics in addition to clinical features of NS, and the growth response to GH treatment by using a nationwide registiration system. Children and adolescents diagnosis with NS were included to study. Laboratory assesment including standard GH stimulation tests result were evaluated. Height increment of patients with or without GH treatment were analyzed after three years of therapy. A total of 124 NS patients have been entered the web-based system. Short stature and tipical face appearence are most encountered diagnostic features of our patients. Long-term follow-up of 84 patients were evaluated. Among them 47 patients received rhGH. Height SDS increased from -3,62±1,14 to -2,85±0,96 after three years of therapy. Significant differences was observed according to nonGH-treated patients. PTPN11 gene were analyzed 61 of patients, and 64% had mutation. Height SDS at admission were similar in patients with or without PTPN11 gene mutation. In short statured patients with different systemic clinical features, diagnosis of NS should be keep in mind. GH therapy is effective for improvement of short stature especially in the first two year treatment. However this effect is under 0.5 SD heigt SD increment which is a relevant indicator of good response to GH therapy. We suggest that optimisation of growth hormone therapy and final height data are needed for this patients.