title: Prader-Willi syndrome: a review of clinical, genetic, and endocrine findings.
abstract: BACKGROUND
  Prader-Willi syndrome (PWS) is a multisystemic complex genetic disorder caused by lack of expression of genes on the paternally inherited chromosome 15q11.2-q13 region. There are three main genetic subtypes in PWS: paternal 15q11-q13 deletion (65-75 % of cases), maternal uniparental disomy 15 (20-30 % of cases), and imprinting defect (1-3 %). DNA methylation analysis is the only technique that will diagnose PWS in all three molecular genetic classes and differentiate PWS from Angelman syndrome. Clinical manifestations change with age with hypotonia and a poor suck resulting in failure to thrive during infancy. As the individual ages, other features such as short stature, food seeking with excessive weight gain, developmental delay, cognitive disability and behavioral problems become evident. The phenotype is likely due to hypothalamic dysfunction, which is responsible for hyperphagia, temperature instability, high pain threshold, hypersomnia and multiple endocrine abnormalities including growth hormone and thyroid-stimulating hormone deficiencies, hypogonadism and central adrenal insufficiency. Obesity and its complications are the major causes of morbidity and mortality in PWS.
  
  
  METHODS
  An extensive review of the literature was performed and interpreted within the context of clinical practice and frequently asked questions from referring physicians and families to include the current status of the cause and diagnosis of the clinical, genetics and endocrine findings in PWS.
  
  
  CONCLUSIONS
  Updated information regarding the early diagnosis and management of individuals with Prader-Willi syndrome is important for all physicians and will be helpful in anticipating and managing or modifying complications associated with this rare obesity-related disorder.
authors.affiliation: Department of Pediatrics, Winthrop University Hospital, 101 Mineola Blvd, 2nd Floor, Mineola, NY, 11501, USA. moris.angulo@gmail.com.
authors.forename: M A
authors.initials: MA
authors.lastname: Angulo
authors.affiliation: Department of Psychiatry and Behavioral Sciences and Pediatrics, University of Kansas Medical Center, 3901 Rainbow Blvd, MS 4015, Kansas City, KS, 66160, USA. mbutler4@kumc.edu.
authors.forename: M G
authors.initials: MG
authors.lastname: Butler
authors.affiliation: Department of Pediatrics, Winthrop University Hospital, 120 Mineola Blvd, Suite210, Mineola, NY, 11501, USA. mcataletto@winthrop.org.
authors.forename: M E
authors.initials: ME
authors.lastname: Cataletto
mesh_terms: D006801:Humans; D011218:Prader-Willi Syndrome / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology
keywords: Chromosome 15 abnormalities; Endocrine disturbances; Genomic imprinting; Hypogonadism; Obesity; Prader-Willi syndrome; Short stature