Endocrine Abstracts

JOINT1404

Introduction: Noonan syndrome (NS) is a relatively common disease with an incidence estimated to be from 1 in 1000 to 1 in 2500 live births. It is a genetically heterogeneous autosomal dominant malformation syndrome. Growth impairment is a common manifestation of NS. In a few studies, recombinant human GH (rhGH) treatment has been shown to increase growth and adult height (AH).

Objectives: To evaluate the effect of rhGH treatment in children with NS and to identify the best indicators of the outcome of this treatment.

Patients and Methods: This is a 24-year-long, monocentric cohort study. Children with NS were followed up from January 2000 to December 2024 in the Pediatric Endocrine Unit, Department of Pediatrics, University Hospital Centre “Mother Teresa”, Albania. Patients with NS who were treated with growth hormone until near adult height (NAH) were included in the analysis of this study. We evaluated growth indicators (especially height) before treatment (at the time of starting treatment), during the treatment (evaluating these indicators for each year of treatment), and after the rhGH treatment for patients who completed treatment with rhGH. Growth indicator data were processed using Anthro-plus software, and statistical analysis was performed using SPSS.

Results: During the period mentioned above, 25 patients with NS have been treated with rhGH. There were 19 (73,08%) males and 7 (26,92%) females. The age at which rhGH treatment started was 10,08±4,12 years. The Bone age was 7,38±3,54 years. HAZ at the beginning of therapy was -3,65±1.17 z-score. Sixteen out of 26 (61,54%) have completed the treatment after the meantime treatment duration of 5,18±2.18 years with the mean dose of rhGH at 0.24 IU/week. Their height changed from -3,81±0,83 z-score to -2,56±1,55 z-core, gaining about 1,25±1,43 z-score (p-value 0,003). Despite the late start of treatment, significant height gains were achieved, with a minority (37.5%) reaching the target height range. The NAH was found to correlate well with the adult predicted height, as well as the HAZ score at the start of treatment, the age at the beginning of treatment, the change in the HAZ score during puberty, the duration of GH treatment, and the bone age at the start of treatment.

Conclusions: Our study results provide valuable insights about the effectiveness of rhGH treatment in patients with NS, enlightening us on the factors influencing their height outcomes better.

Keywords: Noonan syndrome; recombinant human growth hormone; HAZ (Height for Age Z-score); near adult height