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HGH DISORDER/GIGANTISM
http://www.nlm.nih.gov/medlineplus/ency/article/001174.htm
http://www.gigantism.com/robert_wadlow.jpg
http://withfriendship.com/images/g/31066/Gigantism-image.jpg
“Gigantism is abnormally large growth due to an excess of growth
hormone during childhood, before the bone growth plates have closed.”
GIGANTISM- caused by over-production on hGH
 Usually caused by a tumor on the pituitary gland.
o Can also be caused by…
 Multiple endocrine neoplasia (MEN) type I is an inherited
disorder in which one or more of the endocrine glands are
overactive or form a tumor. Endocrine glands most commonly
involved include:
 Pancreas
 Parathyroid
 Pituitary
 Mutations in certain tumor-suppressing-genes, which can
easily lead to endocrine system tumors
 Mostly causes rapid growth in the hands, face, and feet
 A tumor on your pituitary gland essentially convinces your body that you do
not have enough human growth hormone, and it continually releases it
causing you to grow very quickly.
 The child will grow in height, as well as in the muscles and organs. This
excessive growth makes the child extremely large for his or her age.
o Other symptoms include:
o Delayed puberty
o Double vision or difficulty with side (peripheral) vision
o Frontal bossing and a prominent jaw
o Headache
o Increased sweating
o Irregular periods (menstruation)
o Large hands and feet with thick fingers and toes
o Release of breast milk
o Thickening of the facial features
o Weakness
 Damage to the pituitary may lead to low levels of other hormones, including:
o Cortisol
o Estradiol (girls)
o Testosterone (boys)
o Thyroid hormone
2 current technologies used to diagnose or treat the disorder.
Radiation therapy has been used to return the hormone levels back to normal, but it
does take approximately 5-10 years to be fully effective and it usually leads to the
other pituitary hormones levels to decrease.
When the pituitary tumor has clearly distinguished borders surgery is the better
choice of treatment and can cure numerous cases.
However, when surgery is not an option, the most effective mediations are
somatostatin analogs, like octreotide or long-acting lanreotide.
- The negative feedback loop looks something like this:
|Anterior pituitary| --> hGH --> |basically everywhere|
- It's affected right at the AP, because the AP does not stop releasing hGH
- Here's the most common result of an overproduction of hGH: a human being that
retains normal body proportions but is taller that is usual; some people affected
with gigantism can reach 2.4 metres, or about 8 feet.
- If overproduction of hGH continues after bones have completed growth, something
called acromegaly can result. Face and ribs widen, hands enlarge, and
cardiovascualr and breathing problems can occur, as well as colon cancer, diabetes
due to sugar intolerance, and muscle weakness.
- Dwarfism is mostly the same as Gigantism, except in reverse. During childhood, the
anterior pituitary releases too little hGH, and the person, while commonly retaining
normal body proportions, is much shorter than usual, often below four feet.
- The feedback loop is the same, except the AP does not release hGH to begin with.
- This is sometimes caused by genetic mutations, damage to the pituitary gland, or
poor nutrition.
- Puberty may be delayed for several years, or not occur at all.
- Growth is slow or virtually non-existent.