Mondo Description Prader-Willi-like syndrome is a rare, genetic, endocrine disease characterized by manifestations of a Prader-Willi syndrome phenotype (including obesity, hyperphagia, hypotonia, psychomotor delay, intellectual disability, small hands/feet, hypogonadism, growth hormone deficiency and characteristic facial features) ocurring in the absence of 15q11-q13 genomic abnormalities.