Mondo Description Prader-Willi syndrome is a rare genetic disorder characterized by hypothalamic-pituitary abnormalities with severe hypotonia during the neonatal period and first two years of life and the onset of hyperphagia with a risk of morbid obesity during infancy and adulthood, learning difficulties and behavioral problems or severe psychiatric problems.

Disease Ontology Description A chromosomal disease that is characterized by weak muscle tone, feeding difficulties, poor growth, and delayed development. Beginning in childhood, affected individuals develop an insatiable appetite, which leads to chronic overeating and obesity.