Prader-Willi syndrome: a single center's experience in Korea

PURPOSE: Prader-Willi syndrome (PWS) is a complex genetic disorder that results from the lack of paternally expressed genes in the chromosome 15q11-q13 region. This study was performed to delineate the clinical features of PWS infants and toddlers and the effects of two-year growth hormone (GH) treatment according to gender and age at the start of treatment. METHODS: The clinical characteristics and the results of the GH treatment were reviewed retrospectively for 30 PWS patients diagnosed by molecular genetic testing and clinical manifestations. RESULTS: The mean age at diagnosis with PWS was 13.7 months (2-47 months of age). All patients showed the characteristics of facial dysmorphism, including brown hair and almond-shaped eyes. Most patients showed developmental delays/mental retardation (93.3%), cryptorchidism (75%), feeding problems in infancy (73.3%), and neonatal or infantile hypotonia (66.7%). Among 30 patients, 14 PWS infants and toddlers had been treated with GH for more than two years. Two years of GH treatment resulted in an improvement in head circumference-standard deviation score (HC-SDS), body weight-SDS, insulin-like growth factor-1 (IGF-1) SDS, IGF binding protein-3 (IGFBP-3) SDS, lean body mass, and bone mineral content, especially in IGFBP-3 SDS and motor development in PWS patients younger than two years of age. There was significant increase in IGF-1 SDS and IGFBP-3 SDS among male PWS patients after GH treatment. CONCLUSION: Our study showed increases in IGFBP-3 SDS and an improvement in motor development among individuals under two years of age after GH treatment, and significant difference in IGF-1 SDS and IGFBP-3 SDS by gender.