Prader-Willi syndrome is a
genetic disorder occurring in 1 in 10,000-16,000 live-born infants. In the general population, approximately 60 people in every 1,000,000 are affected. The condition is characterized by short stature, low lean body mass,
muscular hypotonia,
mental retardation, behavioral abnormalities, dysmorphic features, and excessive appetite with progressive
obesity. Furthermore, morbidity and mortality are high, probably as a result of gross
obesity. Most patients have reduced GH secretory capacity and
hypogonadotropic hypogonadism, suggesting hypothalamic-pituitary dysfunction. Replacement of GH and/or
sex hormones may therefore be beneficial in
Prader-Willi syndrome, and several clinical trials have now evaluated GH replacement
therapy in affected children. Results of GH treatment have been encouraging: improved growth, increased lean body mass, and reduced fat mass. There was also some evidence of improvements in respiratory function and physical activity. The long-term benefits of GH treatment are, however, still to be established. Similarly, the role of
sex hormone replacement
therapy needs to be clarified as few data exist on its efficacy and potential benefits. In summary,
Prader-Willi syndrome is a disabling condition associated with GH deficiency and
hypogonadism. More active treatment of these endocrine disorders is likely to benefit affected individuals.