Gigantism

=Gigantism= =Root cause of the disease: Gigantism is caused by an over secretion of growth hormone from the pituitary gland during childhood. Growth hormone binds to receptors in target cells and makes them grow larger and divide faster. This is usually because a tumor exists in the pituitary gland. The hormone is released from the pituitary and then spread to bone/muscle/fat, but messages to release the hormone come from the hypothalamus (so this can be caused from a defect in either part of the system) This disease is not to be confused with Acromegaly, which is an over secretion of growth hormone during adulthood (where long bones have ossified and maximum height has been reached)= =Affected cell types/tissues/organs/systems: Over secretion of growth hormone (GH) during childhood affects many of the somatic cells in the body, specifically those of the muscle, bone, and adipose tissue. It affects these tissues by enlarging cells and making them divide quicker. This is a disease of the endocrine system, but the affects are conferred on the rest of the body. Also since GH is involved in protein synthesis, and up regulating cellular use of fat and down regulating cellular use of carbohydrates, gigantism can cause some disturbances in metabolism.= =Historical Background: The term and idea of a “giant” has been around since ancient human history. Since gigantism can be easily observed and diagnosed, this disorder has most likely been discovered long ago. However, the cause of the disease was most likely uncovered with the understanding of how pituitary growth hormone works. The genetic basis of the disease is still being researched. Some famous victims include famous professional wrestler Andre Rene Roussimoff (“Andre the Giant”), one of the tallest basketball player ever in Gheorge Muresan, actor Matthew Mcgrory, and people who hold records in being the tallest human beings.= =Common symptoms:= =- Excessive growth in height/muscle/organs= =- Metabolic disturbances=

- Delayed puberty - Double vision or difficulty with side (peripheral) vision - [|Frontal bossing] and a prominent jaw - [|Headache] - Increased sweating - Irregular periods (menstruation) - Large hands and feet with thick fingers and toes - Release of breast milk - Thickening of the facial features - Weakness - Brain Surgery: Removal of pituitary tumor - Medicine: bodily hormonal analogs that reduce release of GH - Radiation Therapy Most of the current research has to do with the genetic component of gigantism, treatment/cure options for gigantism, and gigantism in other species. One 2008 study showed Pegvisomant, a growth hormone receptor antagonist to be effective in treating children who have been diagnosed with gigantism (Goldberg et al, 2008). In the 2012 review article, “Familial gigantism” the history of gigantism and its genetic determination are explored (Herder, 2012).
 * Possible symptoms**
 * Standard Treatments**
 * Current Research**

References
 * 1) **Herder WW** (2012) Familial gigantism. Clinics **67**:29-32
 * 2) **Goldberd N, Racine MS, Thomas P, Degnan B, Chandler W, Barkan A** (2008) Treatment of Pituitary Gigantism with the Growth Hormone Receptor Antagonist Pegvisomant. Journal of Clinical Endocrinology and Metabolism **93**: 2953-2956
 * 3) //Holes’s Anatomy and Physiology//, 12th Ed. Authors: David Shier, Jackie Butler, Ricki Lewis. McGraw-Hill Publishing Company

Figures

Effects of GH on metabolism. http://www.nature.com/nrendo/journal/v3/n3/fig_tab/ncpendmet0427_F1.html

Flowchart of GH hormonal response



Complicated. signaling pathway of GH effect on gene expression http://www.sabiosciences.com/pathway.php?sn=Growth_Hormone_Signaling