What are the genetic changes related to leptin receptor deficiency ?
Leptin receptor deficiency is caused by mutations in the LEPR gene. This gene provides instructions for making a protein called the leptin receptor, which is involved in the regulation of body weight. The leptin receptor protein is found on the surface of cells in many organs and tissues of the body including a part of the brain called the hypothalamus. The hypothalamus controls hunger and thirst as well as other functions such as sleep, moods, and body temperature. It also regulates the release of many hormones that have functions throughout the body.  The leptin receptor is turned on (activated) by a hormone called leptin that attaches (binds) to the receptor, fitting into it like a key into a lock. Normally, the body's fat cells release leptin in proportion to their size. As fat cells become larger, they produce more leptin. This rise in leptin indicates that fat stores are increasing. In the hypothalamus, the binding of leptin to its receptor triggers a series of chemical signals that affect hunger and help produce a feeling of fullness (satiety).  LEPR gene mutations that cause leptin receptor deficiency prevent the receptor from responding to leptin, leading to the excessive hunger and weight gain associated with this disorder. Because hypogonadotropic hypogonadism occurs in leptin receptor deficiency, researchers suggest that leptin receptor signaling is also involved in regulating the body's response to hormones that control sexual development, and that this response is affected by LEPR gene mutations. However, the mechanism of this effect is unknown.  Leptin receptor deficiency is a rare cause of obesity. Researchers are studying the factors involved in more common forms of obesity.