Prader-Willi syndrome /prä″dər wil″ē/ [A. Prader, 20th-century Swiss physician; H. Willi; Gk, syn, together, dromos, course] , a congenital metabolic condition characterized by hypotonia, hyperphagia, marked obesity, hypogonadism, and cognitive impairment. When diabetes mellitus occurs with the other symptoms, the condition is called Royer’s syndrome. Administration of growth hormones may accelerate growth and improve strength. Testosterone may increase penis size, and puberty can be accomplished with hormone replacement. See also Angelman’s syndrome.
