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$Unique_ID{BRK03792}
$Pretitle{}
$Title{Growth Hormone Deficiency}
$Subject{Growth Hormone Deficiency GHD Turner Syndrome Cystic Fibrosis Down
Syndrome CHARGE association Laron Dwarfism}
$Volume{}
$Log{}
Copyright (C) 1990 National Organization for Rare Disorders, Inc.
866:
Growth Hormone Deficiency
** IMPORTANT **
It is possible that the main title of the article ( Growth Hormone
Deficiency) is not the name you expected. Please check the SYNONYM listing
to find the alternate names and disorder subdivisions covered by this
article.
Synonyms
GHD
Information on the following diseases can be found in the Related
Disorders section of this report:
Turner Syndrome
Cystic Fibrosis
Down Syndrome
CHARGE association
Laron Dwarfism
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.
Growth Hormone is manufactured in the pituitary gland. If it is missing
or reduced in quantity during infancy or childhood, it results in growth
retardation, short stature and other maturation delays.
Growth Hormone Deficiency (GHD) causes an absence or delay of lengthening
and widening of the skeletal bones inappropriate to the chronological age of
the child. A sufficient quantity of growth hormone is required during
childhood to maintain growth and normalize sexual maturity. In some cases
the onset of the disorder occurs prenatally (before birth), and in others the
condition occurs months or years later. Laboratory testing is necessary
before a diagnosis of Growth Hormone Deficiency is made because growth and
maturity delays can be caused by a wide variety of other factors, including
normal genetic influences.
Symptoms
Growth increments are the most important criteria in the diagnosis of Growth
Hormone Deficiency. Normal levels of growth usually follow a pattern and if
growth during a recorded six to twelve month period is within those levels it
is unlikely that a growth disorder exists.
Growth in the first six months of life is usually 16 to 17 cm. and in the
second six months approximately 8 cm. During the second year 10 or more cm
is normal. Growth in the third year should equal 8 cm or more and in the
fourth year 7 cm. In the years between four and ten, an average of 5 or 6 cm
is normal. Ten percent deviation in these norms is the standard in assessing
a growth abnormality. If a child falls below the ten per cent deviation in
growth he/she should then be tested for abnormally low levels of growth
hormone.
The child with GHD is usually of normal weight and length at birth. The
infant may become hypoglycemic (low blood sugar) during the newborn period.
If male, the child may have a small penis. Symptoms that children with GHD
usually have in common are abnormal rates of development of facial bone, slow
tooth eruption, delayed skeletal development, fine hair and poor nail growth.
They may also experience obesity, a high pitched voice and delayed closure of
the front bones of the skull (fontanels).
Causes
The Growth Hormone gene is located on the long arm of chromosome 17. This
knowledge makes genetic testing and counseling possible.
Growth Hormone Deficiency occurs in some children for no apparent reason.
In others it may be inherited or run in families (familial). There are
several types of GHD:
Growth Hormone Deficiency IA is characterized by growth retardation
before birth (prenatally). The child is small in relation to it's brothers
and sisters. The infant usually has a normal response to administration of
human growth hormone (hGH) at first, then develops antibodies to the hormone.
This form of GHD results in very short adults. It is inherited as an
autosomal-recessive trait.
Growth Hormone Deficiency IB is similar to IA, however there is some
growth hormone (GH) present in the child at birth. The child may respond to
hGH treatments. It is inherited as an autosomal-recessive trait.
Growth Hormone Deficiency IIB is similar to IB, however, it is inherited
through an autosomal-dominant mode.
Growth Hormone Deficiency III is similar to the above, however, it is
inherited through X-linked transmission affecting only males.
Human traits, including the classic genetic diseases, are the product of
the interaction of two genes, one received from the father and one from the
mother.
In dominant disorders a single copy of the disease gene (received from
either the mother or father) will be expressed "dominating" the other normal
gene and resulting in the appearance of the disease. The risk of
transmitting the disorder from affected parent to offspring is fifty percent
for each pregnancy regardless of the sex of the resulting child.
In recessive disorders, the condition does not appear unless a person
inherits the same defective gene for the same trait from each parent. If one
receives one normal gene and one gene for the disease, the person will be a
carrier for the disease, but usually will not show symptoms. The risk of
transmitting the disease to the children of a couple, both of whom are
carriers for a recessive disorder, is twenty-five percent. Fifty percent of
their children will be carriers, but healthy as described above. Twenty-five
percent of their children will receive both normal genes, one from each
parent, and will be genetically normal.
In X-linked recessive disorders are conditions which are coded on the X
chromosome. Females have two X chromosomes, but males have one X chromosome
and one Y chromosome. Therefore, in females, disease traits on the X
chromosome can be masked by the normal gene on the other X chromosome. Since
males only have one X chromosome, if they inherit a gene for a disease
present on the X, it will be expressed. Men with X-linked disorders transmit
the gene to all their daughters, who are carriers, but never to their sons.
Women who are carriers of an X-linked disorder have a fifty percent risk of
transmitting the carrier condition to their daughters, and a fifty percent
risk of transmitting the disease to their sons.
Affected Population
Growth Hormone Deficiency affects males and females equally except for GHD
III which affects only males. It is, however, associated very closely with
other disorders such as:
Down syndrome, CHARGE association, cystic fibrosis, chronic renal failure
and Turner syndrome to name a few. There may be approximately 10,000 to
15,000 children in the United States with pituitary dwarfism caused by GHD.
Related Disorders
Symptoms of the following disorders can be similar to those of Growth Hormone
Deficiency. Comparisons may be useful for a differential diagnosis:
Turner Syndrome is a genetic disorder affecting females which is
characterized by a lack of sexual development, small stature, possible mental
retardation, a webbed neck, heart defects, and various other congenital
abnormalities. Individuals have an XO karyotype; i.e.; they have neither the
second X chromosome that characterizes females nor the Y chromosome of males.
Despite the unusual genetic karyotype, people with Turner syndrome are
females. (For more information on this disorder, choose "Turner" as your
search term in the Rare Disease Database).
Cystic Fibrosis is an inherited disorder that affects the exocrine, or
outward-secreting glands of the body. It affects children and young adults.
The main consequences are related to the mucus producing glands. The
secreted mucus is thick and sticky, clogging and obstructing air passages in
the lungs and pancreatic bile ducts. Cystic Fibrosis also causes dysfunction
of salivary and sweat glands. There may also be decreased appetite, weight
loss, failure to gain weight or grow normally, decreased exercise tolerance
and enlarged and blue finger tips (digital clubbing). (For more information
on this disorder, choose "Cystic Fibrosis" as your search term in the Rare
Disease Database).
Down Syndrome is the most common and readily identifiable genetic
condition associated with mental retardation. It is caused by a chromosomal
abnormality. One additional chromosome is present in each cell and this
extra genetic material changes the orderly development of body and brain.
There are over 50 clinical signs of Down syndrome, but it is rare to find all
or even most of them in one person. Some common characteristics include:
Poor muscle tone
Slanting eyes with epicanthic folds
Growth retardation with short adult height
Transverse crease on the palm
Short neck
Small head
Small mouth
Flat nose bridge
(For more information on this disorder, choose "Down" as your search term
in the Rare Disease Database).
CHARGE Association is a very rare disorder characterized by a variety of
symptoms. At least four of the following six characteristics are necessary
for the diagnosis of CHARGE Association: Coloboma of the iris, Heart
Disease, Atresia of the choanae, Retarded growth and development and central
nervous system abnormalities, underdevelopment of the Genitals, Ear
abnormalities and loss of hearing. The first initials of Coloboma, Heart,
Atresia, Retardation, Genitals and Ear, compose the word CHARGE. (For more
information on this disorder, choose "CHARGE" as your search term in the Rare
Disease Database).
Laron Dwarfism is characterized by proportionate severe short stature
which is evident at birth or soon after. Along with growth retardation there
are delays in tooth eruption. There is also disproportion between the growth
of the head and jaw, a saddle nose and deep set eyes. Sexual development is
slow but it does occur. The usual age of sexual maturation in boys with
Laron Dwarfism is about 22 years of age. In females with the disorder,
sexual maturation usually takes place between 16 to 19 years of age. Hands
and feet are smaller than normal. Obesity and a high-pitched voice may also
be present. Laron Dwarfism is a disorder of growth hormone receptors. The
body is unable to use the growth hormone that it produces. A high percentage
of the patients have extremely low blood sugar levels (hypoglycemia). (For
more information on this disorder, choose "Laron" as your search term in the
Rare Disease Database).
Therapies: Standard
Testing is very important in determining if the child with growth retardation
does indeed have Growth Hormone Deficiency. The child is tested using one of
the following tests: the insulin-arginine-estrogen test, the
GH-plasma-exercise, the clonidine or the L-dopa and propranolol tests.
When a diagnosis of GHD is made, treatment can then be instituted. The
question of whether short children whose levels of growth hormone have not
been tested, should be treated with human growth hormone (hGH), is very
controversial since commercially available biotechnology engineered human
growth hormone (hGH) is very expensive and many health insurance companies
will not reimburse for the product unless laboratory tests confirm GHD.
Moreover, adverse effects of hGH on healthy short children who do not have a
deficiency of the hormone have not been adequately assessed and long-term
side effects are unknown.
In the past, growth hormone recovered from human cadaver pituitaries was
used. However, because of problems obtaining sufficient quantities and the
possibility of transferring disease, that method is no longer used.
Recombinant (biotechnology engineered) hGH is available on the U.S. market as
Protropin (Genentech) and Humatrope (Eli Lilly), as an injection.
Children with GHD are usually started on small doses of recombinant human
growth hormone as soon as the disorder is recognized. The dosage is
gradually increased to its highest during puberty, and discontinued by
approximately age 17.
Genetic counseling may be of benefit for patients with GHD and their
families.
Therapies: Investigational
Studies continue on the causes and treatment of GHD and other growth related
diseases. Scientists are especially investigating the physiology of growth
hormone receptors which may lead to additional pharmaceutical interventions
in the future.
This disease entry is based upon medical information available through
October 1991. 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 Growth Hormone Deficiency, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783-1783
203-746-6518
The Magic Foundation
1327 N. Harlem Ave.
Oak Park, IL 60302
(708) 383-0808
Human Growth Foundation
7777 Leesburg Pike
P.O. Box 3090
Falls Church, VA 22043
703-883-1773
800-451-6434
Short Stature Foundation
17200 Jamboree Rd., Suite J
Irvine, CA 92714-5828
(714) 474-4554
800-24 DWARF
Little People of America
P.O. Box 633
San Bruno, CA 94066
415-589-0695
(a support group for adults with growth deficiencies)
NIH/National Institute of child Health and Human Development (NICHD)
9000 Rockville Pike
Bethesda, MD 20892
301-496-5133
For Genetic Information and Genetic Counseling Referrals:
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
914-428-7100
Alliance of Genetic Support Groups
35 Wisconsin Circle, Suite 440
Chevy Chase, MD 20815
(800) 336-GENE
(301) 652-5553
References
MENDELIAN INHERITANCE IN MAN, 9th Ed.: Victor A. McKusick, Editor: Johns
Hopkins University Press, 1990. Pp. 377-80, 887-8, 1426-27.
CECIL TEXTBOOK OF MEDICINE, 19th Ed.: James B. Wyngaarden, and Lloyd H.
Smith, Jr., Editors; W.B. Saunders Co., 1990. Pp. 1290-7, 2205.
SMITH'S RECOGNIZABLE PATTERNS OF HUMAN MALFORMATION, 4th Ed.: Kenneth L.
Jones, M.D., Editor; W.B. Saunders Co., 1988. Pp. 614-8, 762-3.
DIAGNOSTIC RECOGNITION OF GENETIC DISEASE, William L. Nyhan, et al.; Lea
& Febiger, 1987. Pp. 706-9, 712, 718.
CLINICAL PEDIATRIC ENDOCRINOLOGY, Solomon A. Kaplan,: W.B. Saunders Co.,
1990. Pp. 1-56.
GROWTH HORMONE THERAPY, Shulman, L, et al.; Am Fam Physician, May, 1990,
(issue 41 (5)). Pp. 1541-6.
BIOSYNTHETIC HUMAN GROWTH HORMONE IN THE TREATMENT OF GROWTH HORMONE
DEFICIENCY., Holcombe, J.H. et al.; Acta Paediatr Scand Suppl, 1990, (issue
367). Pp. 44-8.
URINARY GROWTH HORMONE EXCRETION AS A SCREENING TEST FOR GROWTH HORMONE
DEFICIENCY, Walker, J.M, et al,; Arch Dis Child, January, 1990 (issue 65
(1)). Pp. 89-92.
GROWTH HORMONE FOR SHORT STATURE NOT DUE TO CLASSIC GROWTH HORMONE
DEFICIENCY., Cara, J.F., et al.; Pediatr Clin North Am., December, 1990,
(issue 37 (6)). Pp. 1229-54.