Introduction


Dwarfism is short stature that results from a medical condition. Dwarfism is generally defined as an adult height of 4 feet 10 inches or less. The most typical range in adult height among people with dwarfism is 2 feet 8 inches to 4 feet 8 inches.
Treatments for most dwarfism-related conditions don't increase stature but correct or alleviate complications associated with the disorders.
Many people with dwarfism encounter discrimination and ridicule. Family support, social networks, advocacy groups and adaptive products enable most people with dwarfism to address their challenges.
Most people with dwarfism prefer not to be labeled. However, some people may refer to themselves as dwarfs or little people. The word "midget" is considered a derogatory term.

Signs and symptoms


More than 200 different medical conditions cause dwarfism. Therefore, dwarfism symptoms other than short stature vary considerably across the spectrum of disorders. In general, the disorders are divided into two broad categories.
 Disproportionate dwarfism. If body size is disproportionate, some parts of the body are small and others are of average size or above-average size. Disorders causing disproportionate dwarfism inhibit the development of bones.
 Proportionate dwarfism. A body is proportionately small if all parts of the body are small to the same degree and appear to be proportioned like a body of average stature.

Disproportionate dwarfism

Most people with dwarfism have disorders that cause disproportionately short stature. Usually, this means that a person has an average-size trunk and very short limbs, but some people may have a very short trunk and shortened (but disproportionately large) limbs. The other common characteristic of these disorders is the head being disproportionately larger than the body.
Almost all people with disproportionate dwarfism have normal intellectual capacities. Rare exceptions are usually the result of a secondary factor, such as excess fluid in the brain (hydrocephalus).
About 70 percent of all people with dwarfism have a disorder called achondroplasia, which causes disproportionately short stature. This disorder usually results in:
 An adult height of approximately 4 feet
 An average-size trunk
 Short arms and legs, with particularly short upper arms and legs
 Short fingers, often with a wide separation between the middle and ring fingers
 Limited mobility at the elbows
 A disproportionately large head, with a prominent forehead and flattened bridge of the nose
 Progressive development of bowed legs (genu varum)
 Progressive development of swayed lower back (lordosis)

Proportionate dwarfism

Proportionate dwarfism results from medical conditions present at birth or during early childhood that limit overall growth and development. Therefore, the head, trunk and limbs are all small but of average proportions relative to each other.
Most of these disorders are uncommon, and signs and symptoms of the disorders vary greatly. Because these disorders affect overall growth, many of them result in poor development of one or more body systems. A few disorders causing proportionate dwarfism result in mental retardation.
Growth hormone deficiency is a relatively common cause of proportionate dwarfism. It occurs when the pituitary gland fails to produce an adequate supply of growth hormone, which is essential for regular childhood growth.

Signs and symptoms include:

 Height below the fifth percentile on standard pediatric growth charts
 Slowed growth before age 5
 Periods of little or no change in height
 Adult height usually less than 5 feet
 Delayed or no sexual development during adolescence
Turner syndrome, also relatively common, is a disorder that results in short stature and impaired sexual maturation in females. Signs and symptoms of the disorder may include:
 An average adult height of 4 feet 8 inches
 Undeveloped ovaries
 Excess skin at the neck at birth that usually becomes less noticeable over time
 Puffy hands and feet at birth and during infancy
 Heart and blood vessel defects
 Kidney problems
 No development of breasts or onset of menstruation during adolescence
 Infertility
 Possible difficulty with intellectual tasks dependent on visualizing objects in relation to one another

Causes

Most dwarfism-related conditions are genetic disorders, but the causes of some disorders are unknown. Most occurrences of dwarfism result from a random genetic mutation in either the father's sperm or the mother's egg rather than being in one of the parent's complete genetic makeup.

Achondroplasia

For example, about 80 percent of people with achondroplasia are born to parents of average height. A person with achondroplasia and with two average-size parents received one mutated copy of the gene associated with the disorder and one normal copy of the gene. A person with the disorder may pass along either a mutated or normal copy to his or her own children.

Turner syndrome

Turner syndrome occurs because of a random deletion or severe alteration of an X chromosome, either in the sperm or egg. (The X chromosome is one of two chromosomes that determine the sex of a person. A female inherits an X chromosome from each parent, and a male inherits a Y chromosome from his father and an X chromosome from his mother.) A girl with Turner syndrome has only one fully functioning copy of the female sex chromosome rather than two.

Growth hormone deficiency

The cause of growth hormone deficiency can sometimes be traced to a genetic mutation or injury, but for most people with the disorder, no cause can be identified.
Other causes of dwarfism include deficiencies in other hormones and poor nutrition.


When to seek medical advice

Signs and symptoms of disproportionate dwarfism are often present at birth or early in infancy. Proportionate dwarfism may not be immediately apparent. If your child's growth seems to be delayed, talk to your pediatrician.
Screening and diagnosis
Your pediatrician will examine a number of factors in order to assess your child's growth and determine if he or she has a dwarfism-related disorder. For some assessments, your pediatrician may refer you to other doctors, such as pediatricians specializing in bone abnormalities (orthopedics) or hormone dysfunction (endocrinology).

Measurements. A regular part of a well-baby medical examination is the measurement of height, weight and head circumference. At each visit, your pediatrician will plot these measurements on a chart, which indicates the percentile ranking for each measurement and expected growth curve in the future.
This information is important for identifying abnormal growth, such as delayed growth or a disproportionately large head. If any trends in these charts are a concern, your pediatrician may make more frequent measurements over a period of several months.

Appearance. Many distinct facial and skeletal features are associated with each of several dwarfism disorders. Therefore, your child's appearance may also assist your pediatrician in making a diagnosis.

Imaging technology. Your doctor may order radiographic studies, such as X-rays, because certain abnormalities of the skull and skeleton can indicate which disorder your child may have. Various imaging devices may also reveal delayed maturation of bones, as is the case in growth hormone deficiency.
A magnetic resonance imaging (MRI) scan may reveal abnormalities of the pituitary gland or hypothalamus, both of which play a role in hormone function.

Genetic tests. Genetic tests are available for many of the known causal genes of dwarfism-related disorders, but these tests often aren't necessary to make an accurate diagnosis. Your doctor is likely to suggest a test only to distinguish among possible diagnoses when other evidence is unclear or as a part of further family planning.
If your pediatrician believes your daughter may have Turner syndrome, then he or she will order special laboratory tests that assess the state of X chromosomes extracted from blood cells.

Family history. Your pediatrician may take a history of stature in siblings, parents, grandparents or other relatives to help determine whether the average range of height in your family includes short stature.

Hormone tests. Your doctor may order tests that assess levels of growth hormone or other hormones that are critical for childhood growth and development.

Complications

Complications of dwarfism-related disorders can vary greatly, but some complications are common among a number of conditions.
Disproportionate dwarfism
The characteristic features of the skull, spine and limbs shared by most forms of disproportionate dwarfism result in some common problems:
 Delays in motor skills development, such as sitting up, crawling and walking
 Frequent ear infections (otitis media) and risk of hearing loss
 Bowing of the legs (genu varum)
 Difficulty breathing during sleep (sleep apnea)
 Pressure on the spinal cord at the base of the skull
 Crowded teeth
 Progressive severe hunching (kyphoscoliosis) or swaying (lordosis) of the back
 In adulthood, narrowing of the channel in the lower spine (lumbosacral spinal stenosis), resulting in pressure on the spinal cord and subsequent pain or numbness in the legs
 Arthritis in adulthood
 Weight gain that can further complicate problems with joints and the spine and place pressure on nerves
Proportionate dwarfism

With disorders causing proportionate dwarfism, problems in overall growth often result in complications with other poorly developed organs. For example, kidney or heart problems often present in Turner syndrome can have a significant effect on a child's general health. An absence of sexual maturation associated with growth hormone deficiency or Turner syndrome affects not only physical development but also social functioning.

Pregnancy

Women with disproportionate dwarfism may develop respiratory problems during pregnancy. A Caesarean delivery is almost always necessary because the size and shape of the pelvis doesn't allow for vaginal delivery.
Public perceptions
People of average height often hold misconceptions about people with dwarfism. Many wrongly believe that people with dwarfism have limited intellectual abilities or personality disorders. Judging maturity by height rather than age, some people may treat people with dwarfism as children.
There's also a long history of people with dwarfism being treated as spectacles for entertainment. And the portrayal of people with dwarfism in modern movies often resorts to stereotypes.
Children with dwarfism are particularly vulnerable to teasing and ridicule from classmates. Because dwarfism is relatively uncommon, children may feel isolated from their peers.


Treatment

Common surgical treatments

Surgical procedures that may correct problems with bones in people with disproportionate dwarfism include:
 Inserting metal staples into the ends of long bones where growth occurs (growth plates) in order to correct the direction in which bones are growing
 Dividing a limb bone, straightening it and inserting metal plates to hold it in place
 Inserting rods or staples to help correct the shape of the spine
 Increasing the size of the opening in bones of the spine (vertebrae) to alleviate pressure on the spinal cord

Limb lengthening

Some people with dwarfism elect to undergo limb-lengthening surgery. With this procedure, the surgeon divides a long bone into two or more sections, separates the sections slightly and braces the bone and limb with metal "scaffolding." Pins and screws on this frame are adjusted to keep tension between the sections, enabling the bone to grow back together gradually into a complete but longer bone.

This procedure is controversial for many people with dwarfism because, as with all surgeries, there are risks, and because the "correction" in stature may imply there's something wrong with being short.

Hormone therapy

Growth hormone deficiency is treated with injections of a synthetic version of the hormone. Most children receive daily injections for several years until they reach a maximum adult height often within the average adult range for one's family. Treatment may continue throughout adolescence and early adulthood to ensure adult maturation, such as appropriate gain in muscle or fat. The treatment may be supplemented with other related hormones if they are also deficient.


Self-care

Talk with your pediatrician or a specialist about at-home care. Issues particularly critical for children with disproportionate dwarfism include the following:
 Car seats. Use an infant car seat with a firm back and neck supports. Continue using a car seat in the rear-facing direction to the highest weight and height possible (and beyond the recommended age limit).
 Infant carriers and play equipment. Avoid infant devices such as swings, umbrella strollers, carrying slings, jumper seats and backpack carriers that don't support the neck or that curve the back into a C shape.
 Adequate support. Support your child's head and neck when he or she is seated.
 Complications. Monitor your child for signs of ear infection or sleep apnea.
 Posture. Promote good posture by providing a footstool and a pillow for the lower back when your child is sitting.
 Healthy diet. Begin healthy eating habits early to avoid later problems with weight gain.