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.

A stereotypy is a repetitive, simple movement that can be voluntarily suppressed. Stereotypies are typically simple back-and-forth movements such as waving of flapping the hands or arms, and they do not involve complex sequences or movement fragments. Movement is often but not always rhythmic and may involve fingers, wrists, or more proximal portions of the upper extremity. The lower extremity is not typically involved. Stereotypies are more commonly bilateral than unilateral.