Syndrome of Hypotonia-Hypomentia-Hypogonadism-Obesity (HHHO) or Prader-Willi Syndrome

IN 1956, Prader et al¹ described a new syndrome which they called "Ein Syndrom von Adipositas, Kleinwuchs, Kryptorchismus und Oligophrenie nach myatonieartigem Zustand im Neugeborenenalter" (a syndrome of obesity, short growth, cryptorchidism, and mental retardation, with an amyotonia-like condition in the neonatal period). Since then, other cases have been reported^2-24 (Table 1) under various titles. (Synonyms for this condition are: Syndrome of Willi-Prader,⁸ of Willi, Prader, and Labhart,¹⁸ of Prader-Willi,^13-15,23,24 of Prader, Labhart, and Willi,⁷ and of Prader, Labhart, Willi, and Fanconi.²¹ [Fanconi, with Prader, Labhart, and Willi, was coauthor of an exhibit of this syndrome at the Eighth International Congress of Paediatrics, July 22-27, 1956, in Copenhagen.] Some of the more descriptive titles are: hypotonia, mental retardation, obesity, and cryptorchidism associated with dwarfism and diabetes in children⁵; hypogenital dystrophy with diabetic tendency¹²; congenital muscular weakness and hypotonia with mental retardation,