Prader–Willi syndrome (PWS) is a rare genetic disorder with a large range of severe co-morbidities including severe neonatal hypotonia with failure to thrive and dysmorphic features during the first months of life followed by the development of morbid obesity and endocrine disorders related to hypothalamic dysfunction (growth hormone (GH) deficiency, hypogonadism, oxytocin deficiency) associated with learning disabilities and behavioural and psychiatric problems.1 2 Early diagnosis combined with multidisciplinary care, parental guidance and GH treatment prevent precocious and morbid obesity in most cases.3

Since optimisation of the management of obesity and other endocrine disorders in these children, experts now have to deal with other pathological conditions that were less often reported when morbid obesity was the biggest challenge. Indeed, management of psychiatric disorders and other co-morbidities of this highly complex disease, such as scoliosis, requires specific attention. These “new” issues appear as a result of improved knowledge of the natural history of the disease and the use of drugs. GH treatment is now commonly used in children with PWS and has greatly changed the clinical presentation of these children as a result of its efficacy on growth, body composition and muscle strength.4 Sudden and unexplained deaths have been reported in children with or without GH treatment, and the effects of GH are not yet clearly elucidated, but its involvement cannot be ruled out.5 Potential complications of GH …