title: The transition between the phenotypes of Prader-Willi syndrome during infancy and early childhood.
abstract: OBJECTIVE
  Prader-Willi syndrome (PWS) is a genetic disorder historically characterized by two phenotypic stages. The early phenotype in infants is associated with hypotonia, poor suck, and failure to thrive. In later childhood, PWS is associated with intellectual disability, hyperphagia, as well as growth and sex hormone deficiency. Little is known about the transition between phenotypes. This study investigates the nature of the change in infancy and childhood PWS.
  
  
  METHODS
  Forty-six children (22 females, 24 males; mean age 2 y 9 mo, SD 18.9 mo; range 7 mo-5 y) with genetically confirmed PWS participated. Information was obtained on childhood height and weight, and eating behaviour from case notes and by parental interview.
  
  
  RESULTS
  Weight standard deviation scores (SDS) started to exceed height by the end of the first year. Height SDS appeared to fall from near normal at birth until stabilizing below normal around 2 years. Half of the children whose body mass index (BMI) was higher than normal at interview had food interests greater than that of their peers, and the age at which increased age-appropriate eating was first noted was later than the increase of BMI SDS.
  
  
  CONCLUSIONS
  Obesity may develop before the increased interest in food, suggesting underlying physiological factors independent of appetite control may be important.
authors.affiliation: Department of Psychiatry, Cambridge Intellectual and Developmental Disabilities Research Group, University of Cambridge, UK.
authors.forename: Jill V
authors.initials: JV
authors.lastname: Butler
authors.forename: Joyce E
authors.initials: JE
authors.lastname: Whittington
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Holland
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: McAllister
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Goldstone
mesh_terms: D000375:Aging; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002675:Child, Preschool; D018450:Disease Progression; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D006963:Hyperphagia / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D007223:Infant; D007407:Interviews as Topic; D016014:Linear Models; D008297:Male; D010641:Phenotype; D011218:Prader-Willi Syndrome / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology*; D012189:Retrospective Studies