Monogenic Obesity Syndromes Provide Insights Into the Hypothalamic Regulation of Appetite and Associated Behaviors.

Neuronal circuits within the hypothalamus play a critical role in the homeostatic regulation of body weight. By disrupting the development or function of these circuits, human monogenic disorders cause hyperphagia (increased food intake), neuroendocrine abnormalities, impaired sympathetic nervous system activation, and obesity. Some genetic disorders also cause maladaptive behaviors such as anxiety, autism, emotional lability, and aggression, highlighting the role of the specific molecules expressed by these hypothalamic neurons in the regulation of innate behaviors that are essential to survival. These findings inform understanding of a wide range of clinical disorders and highlight the challenges associated with targeting these hypothalamic pathways for weight loss therapy.