Skip to Main Content
  • Become an Access Reviewer
  • Clinical Phenotypes
  • OMMBID Advisory banner
  • Ommbid banner
  • Ommbid latest banner

Abstract

Abstract 

  1. Human growth hormone (hGH, or somatotropin) is essential for normal postnatal growth. It is a 191-amino acid protein that is released from the anterior pituitary gland on stimulation by growth hormone-releasing hormone (GHRH, or somatocrinin), a factor produced by the hypothalamic region of the brain. Like other pituitary hormones, hGH acts on target tissues, in this case primarily the liver, to cause synthesis and release of a second hormone mediator, insulin-like growth factor (IGF) I, also called somatomedin C, into the systemic circulation. IGF-I is a growth-accelerating peptide that acts directly on cartilage to promote bone growth.

  2. Deficiency of human growth hormone (hGH) production causes metabolic alterations and growth failure. While most cases of hGH deficiency are idiopathic, 17 known single gene disorders as well as a variety of other genetic disorders and syndromes are associated with deficiency of hGH or defective action. These genetic disorders are caused by alterations in the hGH gene, alterations of distant loci (such as Pit-1, Prop-1, or GHRHR) that cause hGH deficiency through epistatic effects, or alterations of genes (such as the growth hormone receptor gene (GHR)) that affect the response to hGH.

  3. Deficiency of hGH was treated in the past by replacement with exogenous hGH isolated from cadaver pituitaries. Because of the accompanying danger of transmission of infectious neurodegenerative disease (Creutzfeldt-Jakob disease; MIM 123400), alternative methods of treatment are now used. These include replacement with biosynthetic hGH or, in some cases, treatment with GHRH. The potential for hGH gene therapy has been demonstrated in animals.

  4. Human chorionic somatomammotropin (hCS, or human placental lactogen) has similar biologic activities, but it is much less potent than hGH. During pregnancy, maternal hCS levels are very high and approximately 300 times greater than fetal levels. While human chorionic somatomammotropin (hCS) is thought to be important in maternal carbohydrate and fat metabolism, normal fetal growth occurs in pregnancies in which it is absent.

  5. Two genetic disorders of the hCS loci have been described. While these alterations lead to deficiency or absent hCS production, affected individuals are thought to be asymptomatic.

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

OMMBID Full Site: One-Year Subscription

Connect to the full suite of OMMBID content including new and revised chapters that reflect the latest research, image galleries, clinical phenotypes, and more.

$295 USD
Buy Now

Pay Per View: Timed Access to all of OMMBID

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.