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$Unique_ID{BRK03423}
$Pretitle{}
$Title{Acromegaly}
$Subject{Acromegaly Marie Disease Gigantism Marfan Syndrome McCune-Albright
Syndrome Soto's Syndrome Wermer Syndrome}
$Volume{}
$Log{}
Copyright (C) 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1993 National
Organization for Rare Disorders, Inc.
51:
Acromegaly
** IMPORTANT **
It is possible that the main title of the article (Acromegaly) is not the
name you expected. Please check the SYNONYMS listing to find the alternate
name and disorder subdivisions covered by this article.
Synonyms
Marie Disease
Information on the following diseases can be found in the Related
Disorders section of this report:
Gigantism
Marfan Syndrome
McCune-Albright Syndrome
Soto's Syndrome
Wermer Syndrome
General Discussion
** REMINDER **
The Information contained in the Rare Disease Database is provided for
educational purposes only. It should not be used for diagnostic or treatment
purposes. If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.
Acromegaly is a rare, slowly progressive chronic disorder characterized
by an excess of growth hormone. Symptoms include abnormal enlargement in
bones of the arms, legs, and head. The bones in the jaws and in the front of
the skull are typically the most affected. Acromegaly may also cause
thickening of the soft tissues of the body, particularly the heart and
accelerated growth leading to tall stature.
Symptoms
The symptoms of Acromegaly generally progress slowly after puberty and become
more noticeable during middle age. Facial features gradually get a coarse
appearance caused by the growth of soft tissues and cartilage. The facial
bones become prominent, the jaw protrudes, and an overbite may cause a wide
separation between the teeth. People with Acromegaly eventually get a deep
and husky voice. Overgrowth of bone and enlargement of cartilage
(hypertrophy) in the joints may result in inflammation and the gradual
degeneration of involved joints (osteoarthritis). In some people with
Acromegaly the spine may curve from side to side and from front to back
(kyphoscoliosis).
Acromegaly causes a gradual enlargement of the hands and feet.
Compression of the spinal nerves may lead to a variety of functional
abnormalities and pain. The skin may become dark and there may be an
excessive amount of body hair (hirsutism). In some cases abnormal
enlargement of the heart may lead to congestive heart failure. Other
symptoms of Acromegaly may include abnormal enlargement of the liver
(hepatomegaly), spleen (splenomegaly), and/or kidneys (renal). There may
also be enlargement of the thyroid and/or the adrenal glands.
Approximately 25 percent of people with Acromegaly have elevated blood
pressure (hypertension). Abnormal enlargement of the pituitary gland,
located deep within the brain, may cause headaches, visual abnormalities,
and/or hormonal imbalances. In approximately 50 percent of people with
Acromegaly, excessive levels of growth hormone (GH) secreted by the pituitary
gland may influence the production of insulin by the pancreas. This results
in elevated levels of blood sugar (glucose). Some people with Acromegaly may
have an increased metabolic rate, excessive sweating, and/or an increase in
the production of oil (sebum) by the sebaceous glands in the skin.
Symptoms that may develop late in the course of Acromegaly include muscle
weakness (myopathy) and impaired function of peripheral nerves (nerves that
are outside the brain and spinal cord). Vision may become impaired and
possibly progress to blindness. If untreated, 25 percent of people with
Acromegaly experience an increase in the amount of sugar in their urine
(glycosuria), abnormally excessive thirst (polydipsia), and/or abnormally
increased appetite (polyphagia). When Acromegaly occurs in young adults it
can cause rapid and excessive growth resulting in very tall stature.
Causes
Acromegaly is a rare disorder that may be caused by the growth of a benign
tumor (adenoma) in the pituitary cells that secrete growth hormone (frontal
somatotrophic cells). Symptoms develop due to the excessive release
(hypersecretion) of growth hormone (GH) by the pituitary gland. Less
frequently Acromegaly may be caused by the ineffective control of growth
hormone-secreting cells by the hypothalamus (a gland in the brain that
regulates hormone secretions). Growth hormone-secreting tumors may sometimes
be due to over-stimulation by the hypothalamus.
Acromegaly may also be caused by the biologic drug, Human Growth Hormone
(hGH). This drug is usually prescribed for children with growth hormone
deficiency such as pituitary dwarfism. However, when this drug is used by
people with normal levels of growth hormone (such as normal children who want
to grow taller, or by weight lifters who want to strengthen muscles), it
might cause Acromegaly.
Affected Population
Acromegaly is a rare disorder that affects males and females in equal
numbers. This disorder occurs in approximately 50 to 70 people per million.
Related Disorders
Symptoms of the following disorders can be similar to those of Acromegaly.
Comparisons may be useful for a differential diagnosis:
Gigantism is an abnormal condition characterized by excessive height and
size. This disorder typically occurs before puberty as a result of the over
secretion of growth hormone by the pituitary gland. Gigantism is associated
with enlarged soft tissues and late epiphyseal closure (head of the long
bones), which results in excessive growth during childhood. Height may reach
7 or 8 feet. Low levels of growth hormone may be secreted by the pituitary
gland later in the course of this disorder and result in impaired muscle
function and low levels of hormone secretions by the ovaries or testes.
Sexual development may be normal or it may be affected by the low levels of
circulating sex hormones. In some cases of Gigantism, patients may
experience tingling and/or burning sensations in the arms and/or legs
(peripheral neuropathy).
Marfan Syndrome is a rare inherited disorder that affects the connective
tissues of the heart and blood vessels (cardiovascular system); the
musculoskeletal system (ligaments and muscles) is also affected. The major
features of this disorder include unusually tall stature, and large hands and
feet. People with Marfan Syndrome may have significant cardiovascular
problems including mitral valve prolapse, degeneration and enlargement of the
aorta, and/or a bulge in the wall of the aorta (aortic aneurysm). Other
symptoms may include excessive joint mobility, flat feet, extreme muscle
weakness (hypotonia), a protruding or indented breast bone (sternum), and
curvature of the spine (scoliosis). (For more information on this disorder,
choose "Marfan" as your search term in the Rare Disease Database.)
McCune-Albright Syndrome (Acromegaly and Hyperprolactemia) is a rare
multi-system disorder characterized by the abnormal growth of fibrous bone
tissue (polyostotic fibrous dysplasia). Bones most frequently affected
include those of the arms and legs, pelvis, ribs, and/or the base of the
skull. Symptoms of McCune-Albright Syndrome may include pain, shortening of
the limbs, and/or the appearance of patchy brown spots on the skin (cafe-au-
lait macules). During childhood people with McCune-Albright Syndrome grow
rapidly and become taller than children of equal age. However, growth stops
prematurely so that adults with McCune-Albright Syndrome are shorter than
normal. Early puberty (precocious puberty), as early as three months of age
can occur, and is more common in females than males. (For more information
on this disorder, choose "McCune-Albright" as your search term on the Rare
Disease Database.)
Soto's Syndrome is a rare inherited disorder characterized by abnormally
large birth weight and excessive growth (over the 90th percentile) during the
first 2 to 3 years of life. Physical characteristics may include an
abnormally large and long head, a slight bulge of the forehead, large hands
and feet, wide spread eyes (hypertelorism), and/or downslanting eyes. Other
symptoms of Soto's Syndrome may include clumsiness, an awkward gait, and/or
mild developmental retardation. (For more information on this disorder,
choose "Soto" as your search term in the Rare Disease Database.)
Wermer syndrome (Type I Multiple Endocrine Neoplasia or Polyendocrine
Adenomatosis) is a rare inherited disorder characterized by excessive growth,
multiple tumors, and/or excessive hormone secretion. The symptoms of Wermer
Syndrome may include diarrhea and abdominal pain. Children with this
disorder may have low blood sugar (hypoglycemia); adults may have peptic
ulcers. Occasionally epileptic seizures may also occur.
Therapies: Standard
Acromegaly is usually treated by the partial or total surgical removal of the
pituitary gland. This surgical procedure may also be supplemented by
radiation treatment (proton beam, heavy particle, and supravoltage
irradiation). If the entire pituitary gland is removed, lifelong hormonal
replacement therapy is essential. Growth hormone suppressors (drugs that
depress the production of growth hormone) have been used including the female
sex hormones estrogen or medroxyprogesterone, the phenothiazine derivative
chlorpromazine. Somatostatin (Sandostatin), the natural body substance that
inhibits the secretion of growth hormone, is also used as a treatment for
Acromegaly. Sandostatin has been found to be effective in 50 to 60 percent
of cases of Acromegaly.
In mild cases of Acromegaly or in elderly people with this disorder,
dopamine agonists such as bromocriptine have been found to reduce growth
hormone levels when used as an adjunctive therapy (along with other drugs).
Therapies: Investigational
Treatment of Acromegaly with a somatostatin analog (SMS 201-995), known as
"selective mini-somatostatin" can significantly lower the mean plasma growth
hormone levels when given preoperatively. This drug is able to shrink
invasive pituitary macroadenomas and improve surgical remission rates.
Treatment with this somatostatin analog is available in many research-
oriented medical centers within the United States. More research is needed
before this drug can be approved by the FDA.
This disease entry is based upon medical information through February
1993. Since NORD's resources are limited, it is not possible to keep every
entry in the Rare Disease database completely current and accurate. Please
check with the agencies listed in the Resources section for the most current
information about this disorder.
Resources
For more information on Acromegaly, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
National Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Information Clearinghouse
Box AMS
Bethesda, MD 20892
(301) 495-4484
Human Growth Foundation (HGF)
7777 Leesburg Pike
P.O. Box 3090
Falls Church, VA 22043
(703) 883-1773
(800) 451-6434
References
CECIL TEXTBOOK OF MEDICINE, 19th Ed.: James B. Wyngaarden, and Lloyd H.
Smith, Jr., Editors; W.B. Saunders Co., 1990. Pp. 1234-1236.
TEXTBOOK OF ENDOCRINOLOGY, 8TH ED.: Jean D. Wilson and Daniel W. Foster,
Editors; W.B. Saunders Co., 1992. Pp. 268-290.
ACROMEGALIC HEART DISEASE: INFLUENCE OF TREATMENT OF THE ACROMEGALY ON
THE HEART: R. P. Hayward, et al.; Quarterly Journal Med (January 1987: issue
62(237)). Pp. 41-58.
THE PATHOGENESIS OF ACROMEGALY: CLINICAL AND IMMUNOCYTOCHEMICAL ANALYSIS
IN 75 PATIENTS: E.R. Laws, Jr., et al.; Journal Neurosurg (July 1985: issue
63(1)). Pp. 35-38.
SOMATOSTATIN PROVES EFFECTIVE IN TREATING RESISTANT ACROMEGALY: Andrea
J. Clark; Research Resources Reporter (April 1988). Pp. 5-7.
SOMATOMEDIN-C LEVELS IN TREATED AND UNTREATED PATIENTS WITH ACROMEGALY:
F. Roelfsema, et al.; Clin Endocrinol (Oxford) (February 1987: issue 26(2)).
Pp. 137-144.
ACROMEGALY: J.D. Nabarro; Clin Endocrinol (Oxford) (April 1987: issue
26(4)). Pp. 481-512.
ACROMEGALY, Shlomo Melmed, M.B., CH.B., N Eng J Med, (April 5, 1990,
issue 322 (14)). Pp. 966-977.