ESPE Abstracts

Purpose: Noonan syndrome (NS) is a genetic disorder characterized by specific features including short stature, cardiac defect, and distinctive facial dysmorphism. Human growth hormone (GH) has been used to improve growth in children with NS but there is little information how GH treatment affects height. The aim of this study is to investigate efficacy of GH treatment in Korean children with NS compared to sex and age-matched patients with growth hormone deficiency (GHD).

Methods: Retrospective analysis of the growth during 2 years in NS children with normal GH secretion. Total 17 prepubertal children with NS (boy 10, girl 7) who received GH therapy for at least 2 years were included during 2008 and 2015. The recombinant human was administered at a dose of 50–75 µg/kg/day for 6 days a week subcutaneously. We analyzed height and height velocity before and during GH treatment. The height and height velocity were compared with children with GH deficiency (n=32) matched for age, sex as a control group.

Results: The mean age of patients with NS was 6.34 ± 2.32 years. Mutations in the PTPN11 gene were identified in 11 subjects (64.7%). Mutations in the RAF1 (1 child, 5.8%) and SHOC2 (1 child, 5.8%) genes were also found. No mutations were found in 4 of patients (23.5%). Before starting GH, the height SDS of patients was -2.63 ± 0.72. Height SDS increased from –2.6 ± 0.72, to –1.92 ± 0.88, to –1.57 ± 0.94, respectively, at the first and second year of treatment (P<0.001, respectively). Growth velocity in first year was 8.6 ± 1.9 cm and 7.1 ± 1.1 cm in second years of GH treatment, respectively. The Growth velocity was 9.00 ± 1.35 (cm/yr) in first year and 6.8 ± 1.11 9 (cm/yr) in second year with GH treatment, respectively. There were no significant differences in growth velocity and the change of height SDS with GH treatment between NS and GHD patients.

Conclusions: GH therapy can increase linear growth in Korean prepubertal children with NS. In addition, the growth response of GH in NS patients is similar to children with GHD.