Dwarfism ( ) is a medical disorder, the term being
used to describe a person of
short
stature. It is sometimes defined as a person with an adult
height under 4 feet 10 inches (147 cm). However, this
restriction is problematic since the average height of population
groups differs greatly.
Dwarfism can be caused by over 200 distinct medical conditions ,
and as such the symptoms and characteristics of individual dwarfs
vary greatly. People who are affected by dwarfism are often
referred to as
little people.
Disproportionate dwarfism is characterized by one or more
body parts being relatively large or small in comparison to those
of a normal adult, with growth abnormalities in specific areas
being apparent. In cases of
proportionate dwarfism, the
body appears normally proportioned, but is clearly abnormally
small.
Hypotonia, or a lack of muscle, is
common in dwarfs, but intelligence and lifespan are usually
normal.
Achondroplasia is a bone growth
disorder responsible for 70% of dwarfism cases. In cases of
achondroplasia the limbs are disproportionally short compared to
the trunk (abdominal area), with the head larger than normal and
unique facial characteristics. Conditions in humans characterized
by disproportional body parts are typically caused by one or more
genetic disorders in bone or
cartilage development. Extreme shortness in humans with
proportional body parts usually has a hormonal cause, such as
growth hormone deficiency,
once known as "pituitary dwarfism".
There is no single treatment for dwarfism. Individual abnormalities
such as bone growth disorders can sometimes be treated through
surgery, and some hormone disorders can be treated through
medication, but in most cases it is impossible to treat all the
symptoms of dwarfism. Most of the time lifestyle changes are needed
to cope with the effects of dwarfism. In-home devices like
specialized furniture are often needed to help people with dwarfism
to function normally. Many support groups exist to help sufferers
of dwarfism cope with the challenges they face, and to help them
develop strategies to become independent.
Dwarfism is a highly visible condition that often carries negative
connotations in society. Some believe people afflicted with
dwarfism are intellectually challenged or have personality
disorders. Due to their unusual height, people with dwarfism are
often used as spectacles in entertainment or portrayed with
stereotypes. For a person with dwarfism,
Heightism is a problem that can lead to ridicule
as a child and discrimination as an adult.
Classification
Dwarfism is a medical disorder with the sole requirement being an
adult height under 4 feet 10 inches (147 cm) and it is
almost always classified as to the underlying condition that is the
cause for the short stature. Dwarfism is not necessarily caused by
disease or a genetic disorder; it can simply be a naturally
occurring consequence of a person's genetics. If dwarfism is caused
by a medical disorder, the person is referred to by the underlying
diagnosed disorder. Disorders causing dwarfism are often classified
by proportionality. Disproportionate dwarfism describes disorders
that cause abnormal proportions of the body parts, while
proportionate dwarfism results in a generally uniform stunting of
the body.
Disorders that cause dwarfism may be classified according to one of
hundreds of names, which are usually permutations of the following
roots:
- location
- rhizomelic = root,
e.g., bones of the upper arm or thigh
- mesomelic = middle, e.g., bones of the forearm
or lower leg
- acromelic = end, e.g., bones of hands and
feet.
- micromelic = entire limbs are shortened
- source
- chondro = of cartilage
- osteo = of bone
- spondylo = of the vertebrae
- plasia = form
- trophy = growth
Examples include
achondroplasia,
osseous dysplasia,
chondrodystrophy, and
osteochondrodystrophy.
Characteristics
The universal defining characteristic of dwarfism is an adult
height of less than 4 feet 10 inches. Since those afflicted
with dwarfism have such a wide range of physical characteristics,
oddities in individuals are identified by diagnosing and monitoring
the underlying disorders.
Disproportionate dwarfism is characterized by one or more body
parts being disproportionately large or small compared to the rest
of the body. In
achondroplasia the
trunk is normally sized with the limbs being disproportionately
short, the head being larger than usual, and the forehead being
prominent. Facial features are often affected and individual body
parts may have problems associated with them. Orthopedic problems
can result from multiple conditions such as
diastrophic dysplasia and
pseudoachondroplasia.
Proportionate dwarfism is marked by body parts being proportional
but stunted. Height is significantly below average and there may be
long periods without any significant growth. Sexual development is
often delayed or impaired into adulthood. Unlike disproportionate
dwarfism, mental capacity may be diminished in some cases of
proportionate dwarfism. The overall stunted growth can lead to
impaired intelligence when compared to the physical age.
Physical maleffects of malformed bones vary according to the
specific disease. Many involve joint pain caused by abnormal bone
alignment, or from
nerve compression (e.g.,
spinal stenosis). Early degenerative
joint disease, exaggerated
lordosis or
scoliosis, and constriction of
spinal cord or nerve roots can cause pain and
disability. Reduced
thoracic size can
restrict lung growth and reduce pulmonary function. Some forms of
dwarfism are associated with disordered function of other organs,
such as the
brain or
liver, sometimes severely enough to be more disabling
than the abnormal bone growth.
Mental effects also vary according to the specific underlying
syndrome. In most cases of skeletal dysplasia, such as
achondroplasia, mental function is not impaired in any way.
However, there are syndromes which can affect the cranial structure
and growth of the brain, severely impairing mental capacity. Unless
the brain is directly affected by the underlying disorder, there is
little to no chance of mental impairment that can be attributed to
dwarfism.
The psychosocial disadvantages may be more distressing than the
physical symptoms, especially in childhood and adolescence, but
people with dwarfism vary greatly in the degree to which social
participation and emotional health are affected.
- Social prejudice against extreme shortness may reduce social
and marital opportunities.
- Numerous studies have demonstrated reduced employment
opportunities. Severe shortness is associated with lower
income.
- Self-esteem may suffer and family
relationships may be affected.
- Extreme shortness (in the low 2–3 foot [60-90 cm] range) can
interfere with ordinary activities of daily living, like driving or
using countertops built for taller people. Other symptoms of
dwarfism such as bowed knees and unusually short fingers can lead
to back problems, difficulty in walking, and handling objects.
- Dwarfism is often misunderstood by others, and short people are
often believed to be academically challenged, which leads to a
difficult social life.
Causes
Dwarfism can result from myriad medical conditions, each with its
own separate symptoms and causes. Two disorders, achondroplasia and
growth hormone deficiency (also known as pituitary dwarfism), are
responsible for the majority of dwarfism cases.
Achondroplasia
The most recognizable and most common form of dwarfism is
achondroplasia, which accounts for 70% of
dwarfism cases and produces rhizomelic short limbs, increased
spinal curvature, and distortion of skull growth. Achondroplasia is
an
autosomal dominant disorder
caused by the presence of a faulty
allele in
a person's genome. If a pair of achondroplasia alleles are present,
the result is fatal. Achondroplasia is a mutation in the
fibroblast growth
factor receptor gene 3 (
), which is an inhibitor that regulates bone growth. In cases of
achondroplasia, the FGR3 gene is too aggressive, negatively
impacting bone growth.
Growth hormone deficiency
Growth hormone deficiency (GHD) is a medical condition in which the
body produces insufficient
growth
hormone. Growth hormone, also called
somatotropin, is a
polypeptide hormone which
stimulates
growth and
cell reproduction. If this hormone is lacking, stunted or even
halted growth may become apparent. Children with this disorder may
grow slowly and puberty may be delayed by several years, or even
indefinitely. Growth hormone deficiency has no single definite
cause. It can be caused by mutations of specific genes, damage to
the pituitary gland,
Turner's
syndrome, poor nutrition, or even stress (leading to
psychogenic dwarfism).
Other
Other causes of dwarfism include
Spondyloepiphyseal
dysplasia congenita,
Diastrophic dysplasia,
Pseudoachondroplasia,
Hypochondroplasia,
Primordial dwarfism,
Turner syndrome, and
Osteogenesis imperfecta (OI). Severe
shortness with skeletal distortion also occurs in several of the
mucopolysaccharidoses and
other
storage
disorders.
Diagnosis
Dwarfism is often diagnosed in childhood on the basis of visible
symptoms. A physical examination can usually suffice to diagnose
certain types of dwarfism, but
genetic
testing and diagnostic imaging may be used to determine the
exact condition. In a person's youth, growth charts that track
height can be used to diagnose subtle forms of dwarfism that have
no other striking physical characteristics.
Short stature or stunted growth during youth is usually what brings
the condition to medical attention. Skeletal
dysplasia is usually suspected because of obvious
physical features (e.g., unusual configuration of face or shape of
skull), because of an obviously affected parent, or because body
measurements (arm span, upper to lower segment ratio) indicate
disproportion. Bone X-rays are often key to diagnosing a specific
skeletal dysplasia, but are not the sole diagnostic tool. Most
children with suspected skeletal dysplasias are referred to a
genetics clinic for diagnostic confirmation and
genetic counseling. Since about the year
2000, genetic tests for some of the specific disorders have become
available.
During an initial medical evaluation of shortness, the absence of
disproportion and other clues listed above usually indicates causes
other than bone dysplasias. Extreme shortness with completely
normal proportions sometimes indicates
growth hormone deficiency
(pituitary dwarfism).
Short stature alone, in the absence of any other abnormalities, may
be the result of the distribution of offspring height from
short-statured parents, rather than a symptom of any medical
condition.
Prevention
Many types of dwarfism are impossible to prevent because they are
genetically caused. Genetic conditions that cause dwarfism may be
identified with
genetic testing, by
screening for the specific abnormalities that result in the
condition. However, due to the number of causes of dwarfism, it may
be impossible to determine definitively if a child will be born
with dwarfism.
Dwarfism resulting from malnutrition or a hormonal abnormality may
be treated with an appropriate diet or hormonal therapy. Growth
hormone deficiency may be remedied via injections of Human Growth
Hormone (HGH) during early life, but HGH injections may adversely
affect the cardiac muscles, making them too large or thick to
properly function, causing death through cardiac failure.
Management
Genetic defects of most forms of dwarfism caused by bone dysplasia
cannot be corrected, so therapeutic interventions are typically
aimed at preventing or reducing pain or physical disability,
increasing adult height, or mitigating psychosocial stresses and
enhancing social adaptation.
Forms of dwarfism associated with the endocrine system may be
treated using
hormonal therapy. If
the cause is prepubescent hyposecretion of growth hormone,
supplemental growth hormone may correct the abnormality. If the
receptor for growth hormone is itself affected, the condition may
prove harder to treat.
Hypothyroidism
is another possible cause of dwarfism that can be treated through
hormonal therapy. Injections of thyroid hormone can mitigate the
effects of the condition, but physical complications may be
permanent.
Pain and disability may be ameliorated by physical therapy, braces
or other orthotic devices, or by surgical procedures. The only
simple interventions that increase perceived adult height are dress
enhancements, such as shoe lifts or hairstyle. Growth hormone is
rarely used for shortness caused by bone dysplasias, since the
height benefit is typically small (less than 5 cm [2 in]) and
the cost high. The most effective means of increasing adult height
by several inches is
limb-lengthening surgery, though
availability is limited and the cost is high in terms of money,
discomfort, and disruption of life. Most people with dwarfism do
not choose this option, and it remains controversial. For other
types of dwarfism, surgical treatment is not possible.
Society and culture
Terminology
The appropriate term for describing a person of particularly short
stature (or with the genetic condition achondroplasia) has
historically been ambiguous, and has developed euphemistically over
the past few centuries.
"
Midget," whose etymology indicates a "small
sandfly," came into prominence in the mid-1800s after
Harriet Beecher Stowe used it in her
novels
Sunny Memories of Foreign Lands and
Old Town Folks where she described
children and an extremely short man, respectively. Later, the word
was deemed offensive because it was the descriptive term applied to
P.T. Barnum's
dwarfs used for public amusement during the
freak show era. It is also not considered
accurate as it is not a medical term or diagnosis, though it is
sometimes used as a slang term to describe those who are
particularly short, whether or not they have dwarfism.
The first notable use of the term "dwarf" was by the
Brothers Grimm in their fairy tale
Little Snow White;
Jonathan Swift also used it in
Gulliver's Travels to describe a
giant who was only 20 ft tall compared to his 40 ft
peers. The plural form of "dwarf" for a person with dwarfism is
"dwarfs", while "dwarves" describes the mythical creature. the word
"dwarf" has also been condemned by some as not only inaccurate but
also insensitive due to its mythical and fairy tale origins.
The terms "dwarf", "little person", "LP", and "person of short
stature" are now generally considered acceptable by most people
affected by these disorders.
Art and media depictions
In art, literature, or movies, dwarfs are rarely depicted as
"regular people who are very short" but rather as a species apart.
Novelists,
artists,
and
moviemaker may attach special moral
or aesthetic significance to their "apartness" or
misshapenness.
Artistic representations of dwarfism can be found on
Greek vases and other ancient artifacts,
including
ancient Egyptian art in
which dwarfs are likely to have been seen as a divine
manifestation, with records indicating they could reach high
positions in society.
Depiction of dwarfs is also found in European paintings and many
illustrations.
Many European paintings (especially Spanish
) of the
16th–19th centuries depict dwarfs by themselves or with
others. In the Talmud, it is
said that the second born son of the Egyptian
Pharaoh of the Bible was a
dwarf. Recent scholarship has suggested that ancient
Egyptians held dwarfs in high esteem. Several important
mythological figures of the North American
Wyandot nation are portrayed as dwarfs.
As popular media have become more widespread, the number of works
depicting dwarfs has increased dramatically. Some feel that dwarf
characters are often depicted based on the novelty factor of their
stature rather than on other personal attributes. Dwarfism is
depicted in many books, films, and TV series such as
Austin Powers,
Gulliver's Travels by
Jonathan Swift,
The Wizard of Oz,
Willy Wonka and the
Chocolate Factory,
Little
People Big World,
Harry Potter,
Seinfeld,
In
Bruges,
The Tin Drum by
Günter Grass, and the film
The Station Agent.
See also
References
- University of Pennsylvania, Arts and Sciences: "The
Effect of Adolescent Experience on Labor Market Outcomes: The Case
of Height".
- Science Blog: "Short children more likely to be
bullied at school".
- "Ancient Egypt:Kingdom of the Pharaohs", R. Hamilton,
p. 47, Paragon, 2006, ISBN 1-40548-288-5
- "Ancient Egyptian Medicine",John F. Nunn, University
of Oklahoma Press, 2002, p. 78-79, ISBN 0806135042
- Dwarfs Commanded Respect In Ancient Egypt,
ScienceDaily, 27 Dec 2005
- The Talmud - Chapter Vi. Death Of Jacob And His
Sons--Moses--The Deliverance From Egypt. URL accessed April 23,
2007.
- Trigger, Bruce G., The Children of Aataentsic: A History of
the Huron People to 1660 McGill-Queen's University Press, 1987
ISBN 0-7735-0627-6, p. 529.
- Gulliver's Travels: Complete, Authoritative Text with
Biographical and Historical Contexts, Palgrave Macmillan 1995
(p. 21). The quote has been misattributed to Alexander Pope, who
wrote to Swift in praise of the book just a day earlier.
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