Growth Hormone Therapy in Prader Willi Syndrome – Audit of Age of Initiation Over Time in a Tertiary Centre

Ciara Dolan; Daniel Hardiman; Philip Stewart; Edna Roche

Background: Prader-Willi Syndrome (PWS), is a rare complex, genetic neurodevelopmental disorder characterised by hypotonia, poor feeding, neonatal failure to thrive. Untreated, patients progress to hyperphagia and life-limiting extreme obesity. Growth hormone therapy (GHt) is currently the only licenced therapy in PWS. The consensus statement by Deal et al, suggested GH treatment at around 2-years before the onset of obesity. While there are no data to support a definitive age to commence GHt in PWS, emerging consensus suggests starting treatment at around 2-years and IPWSO suggests before 1-year.

Aim: Comparing age at GHt initiation in children with PWS against the 2019 IPWSO consensus document; identify potential causes of delay in initiating therapy and explore if the age has reduced over time.

Method: A retrospective chart review of children with PWS from July-2023 to September-2023. Demographics, comorbidities, decimal age were recorded. Where the initiation was delayed beyond one-year; reasons for delay were recorded. Tallaght University Hospital’s Audit Committee granted ethical approval.

Results: In the period, 51 patients (25male), aged 0.92-17.16years with PWS were identified, and 4 patients were excluded, due to early charts inaccessibility.

Table 1. Age of Growth-Hormone Therapy Initiation classification
	Number of Patients	Percentage
<1year	8	16%
1-1.5year	12	24%
1.5-2years	2	4%
>2years	23	45%
Not on GHt	2	4%
Excluded Patients	4	8%

Of the two patients not on GHt; one was less than one-year at the time of the audit; one was parents’ choice. Reasons for treatment delay; delayed access to polysomnography (19;47%); awaiting GH stimulation testing (3;8%); management of severe obstructive sleep apnoea (7;18%); unknown, commenced prior to referral (7;18%); parental choice (3;8%).

Table 2. Age of Growth-Hormone Therapy Initiation by year.
	Patient ages(years)	Median Age(years)
2015	2.25, 2.67, 3, 4.16, 4.33, 4.67, 5.58, 9	4.25
2016	0.92, 1.25, 1.33, 2.33	1.29
2017	1.08, 1.5, 3.16, 11.16	2.34
2018	1.25, 5.42	3.34
2019	0.5, 1, 1.08, 9	1
2020	0.5, 0.92, 0.92, 1.08, 1.25, 6, 8	1.17
2021	1.42, 1.5, 4.75	1.5
2022	0.92, 1.25, 2	1.25

Conclusion: In this audit the majority of patients with PWS did not commence GHt prior to 1-year, although 22(44%) started at or before 2-years. Reassuringly the age of commencement of GHt in our centre has reduced in recent years, since 2018. Increased access to polysomnography and expediated management of severe OSA for patients with PWS is required to enable earlier GH initiation to meet the 1-year treatment target.

ESPE Abstracts

P1-252