Growth Hormone Treatment and Its Effect on Height in Pediatric Patients with Different Genotypes of Prader-Willi Syndrome

ABSTRACT

PURPOSE: Differences in phenotypes between the two most common subtypes of Prader-Willi syndrome (PWS) indicate that a distinct response to growth hormone (GH) treatment may exist. To test this hypothesis, we compared the results of GH treatment in individuals with PWS due to uniparental disomy (UPD) to those of individuals with deletions. METHODS: Sixty-five children with PWS who had been treated with GH for more than two years were included in this study. Twenty-one individuals were confirmed as having UPD and 44 individuals had a deletion. Height, body weight, body mass index (BMI), and insulin like growth factor-1 (IGF-I) measurements were recorded before GH treatment and at intervals of 12 months thereafter. RESULTS: After two years of GH therapy, no significant differences were noted for yearly improvements in height standard deviation scores (SDS) between the groups (second year SDS, 0.93 +/- 0.94; deletion, 0.84 +/- 1.31; UPD, P = 0.717). Body weight SDS, BMI SDS, and IGF-I SDS also showed no differences between the two groups. CONCLUSION: Our study showed no significant differences in yearly improvements in height SDS between the deletion and UPD groups, at least for the first two years.