ESPE Abstracts

Introduction: Prader-Willi syndrome (PWS) is a rare imprinting disorder with evidence of increasing incidence. Treatment with recombinant human growth hormone (rhGH) has been shown to improve growth, body composition and final height. It is officially approved by the US Food and Drug Administration since 2000, but still not official indication in many countries.

Aim: The aim of the current study is to assess the results of the rhGH treatment at the end of the first year in PWS patients followed at an Expert center for rare endocrine diseases, participating in the European Reference Network for Rare Endocrine Diseases (Endo-ERN).

Patients and Methods: The study is a retrospective evaluation of regularly followed PWS patients at the Center since 2011 after the start of the official reimbursement in the country. All study participants were treated with rhGH for at least one year. A total of 18 patients with genetically confirmed PWS (11 DEl, 2 UPD, 5 with positive methylation test) participated in the study. The dosing was assessed every 3 - 6 months by attained auxological parameters (weight, height and BMI according to cdc growth reference, BMI after 2 years of age), IGF-1 levels and other safety parameters according to the Recommendations for the Diagnosis and Management of PWS patients (Goldstone, 2008) and the relevant requirements of the National health insurance fund.

Results: The age at diagnosis was from 0.08 to 14 years. The girls’ mean age was 8.0±3.1 years, significantly higher than boys’ (1.9±3.7 years, P=0.05). The mean age at rhGH start was 5.15±4.96 years (0.33-14.66), at a mean dose of 0.025±0.006 mg/kg/d (0.010-0.035). The latter did not change by the end of the 1st year (0.025±0.005 mg/kg/d, 0.017-0.032). The 1st treatment year height gain was 10.01±4.84 cm (2.5-19), more in boys than in girls (P=0.047). SDSIGF-1 before and after one year of treatment increased significantly (-1.62±0.7 vs. 0.72±1.54, P=0.001). SDSBMI decreased significantly during the 1st year of treatment with 0.39±0.51 (from 2.5±1.1 to 2.1±0.94, P=0.005). No adverse events were reported.

Conclusion: The early diagnosis and respectively, earlier start of treatment with rhGH in PWS patients increases initial height gain and provides faster decrease in BMI, especially in boys in our study group. Faster introduction of reimbursed PWS treatment with growth hormone worldwide is warranted as well as improvement of care at expert university affiliated establishments.