Title: Growth hormone therapy improves cognition in children with Prader–Willi syndrome
Abstract: Treatment with growth hormone (GH) prevents cognitive deterioration and improves abstract reasoning and visuospatial skills in children with Prader-Willi syndrome (PWS), according to a group of Dutch researchers.Previous reports showed that GH therapy improves cognition in infants and adults with PWS, as well as in children with GH deficiency, children born small for gestational age and children with Down syndrome.However, the effects of >6 months of GH treatment in children with PWS were unknown.The researchers designed a two-part study to assess the effects of GH therapy on cognition in prepubertal children with a genetically confirmed diagnosis of PWS and no previous exposure to this type of therapy.The study population consisted of 50 patients (21 boys aged 3-14 years and 29 girls aged 3-12 years).The first part of the study was a 2-year randomized controlled trial, in which the children received either 1.0 mg/m 2 of biosynthetic GH daily or no GH therapy.The second part of the study was an analysis of the effects of 4 years of GH therapy: children who received GH during the first part of the study continued the therapy for an additional 2 years, whereas children still naive to GH therapy were treated for 4 years after the first part of the study had finished.The researchers measured the children's cognitive function every 2 years, using short versions of the WISC-R intelligence scale subtests for children aged >7 years and short versions of