ESPE Abstracts

Aim: There is a current lack of international guidelines for managing the endocrine aspects of Noonan syndrome (NS). A clinical practice survey was developed to identify knowledge gaps and differences in the management of patients with NS across Europe.

Materials and Methods: A 60-question clinical practice survey was developed for clinical geneticists, paediatric endocrinologists and paediatric cardiologists directly involved in treating and managing patients with NS. The survey was implemented via the SurveyMonkey online platform and circulated by several European and national specialist societies. Contingency tables and the Chi-Squared test for independence were used to examine differences between specialities and countries.

Results: Responses from 364 physicians from 20 European countries were included in this analysis: endocrinologists (40%), geneticists (30%), and cardiologists (30%). To monitor growth, endocrinologists tend to refer to national growth charts for the general population, and geneticists generally use NS-specific growth charts. Many endocrinologists (52%) perform growth hormone (GH) stimulation tests in patients with NS and short stature with low IGF1 levels (10% never perform these tests, and 36% always perform these tests regardless of IGF1 levels). Sixty six percent of endocrinologists begin GH treatment for short patients in early childhood (4–6.9 years). Half of them (55%) considered a threshold for GH treatment of -2 standard deviation score (SDS) according to national growth charts. Respondents from all specialities had the following concerns about GH treatment: hypertrophic cardiomyopathy (HCM) (59%), increased risk of malignancy (46%), and limited efficacy (31%). There were significant discrepancies between respondents regarding the meaning of HCM as a contraindication for GH. When asked if they consider HCM a contraindication to the use of GH therapy, many skipped this question, and of those who replied, many selected the option ‘cannot answer’, suggesting a high level of uncertainty. There were 21 reported adverse cardiac responses to GH treatment from <10% of respondents. While the majority had not encountered malignancies during GH treatment, 6 were reported (4 brain tumours, including 3 dysembryoplastic neuroepithelial tumours, and 2 leukaemias). Around half of the surveyed endocrinologists expected GH treatment to produce a typical final height gain of 1–1.5 SDS.

Conclusion: For the first time, results from this survey describe current clinical practice for managing the endocrine aspects of NS within Europe. These data will allow us to identify gaps in the knowledge of this rare genetic disorder, highlighting important topics for education and further research.