Dwarfism

1 What is Dwarfism?

Dwarfism is short stature that occurs as a result of a genetic or medical condition. It is described as an adult height of 4 feet 10 inches (147 centimeters) or less.

The average height for an adult with dwarfism is 4 feet (122 cm). Dwarfism can be caused my many medical conditions.

These disorders can be divided into:

  • Disproportionate dwarfism - in which some parts of the body are small while others are the average size or above average size. Conditions that cause this type of dwarfism inhibit the development of bones.
  • Proportionate dwarfism- in which all parts of the body are small to the same degree and appear to be proportioned like a body of the average structure.

Conditions that cause this type of dwarfism are present at birth or may occur in early childhood. They may limit the overall growth and development of a child.

It is necessary to be sensitive to a person who has this disorder as some people prefer the term "short stature" over "dwarf" or "dwarfism".

2 Symptoms

Signs and symptoms, other than short stature, vary considerably depending on the type of dwarfism.

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.

In these disorders, the head is disproportionately large compared with 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 around the brain (hydrocephalus). The most common cause of dwarfism is a disorder called achondroplasia.

This condition which causes disproportionately short stature.

This disorder usually results in the following:

  • An average-size trunk
  • Short arms and legs, with particularly short upper arms and upper 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 a flattened bridge of the nose
  • Progressive development of bowed legs
  • Progressive development of swayed lower back
  • An adult height around 4 feet (122 cm)

Another cause of disproportionate dwarfism is a rare disorder called spondylo-epiphyseal dysplasia congenita (SEDC).

Signs may include:

  • A very short trunk
  • A short neck
  • Shortened arms and legs
  • Average-size hands and feet
  • Broad, rounded chest
  • Slightly flattened cheekbones
  • Opening in the roof of the mouth (cleft palate)
  • Hip deformities that result in thighbones turning inward
  • A foot that's twisted or out of shape
  • Instability of the neck bones
  • Progressive hunching curvature of the upper spine
  • Progressive development of swayed lower back
  • Vision and hearing problems
  • Arthritis and problems with joint movement
  • Adult height ranging from 3 feet (91 cm) to just over 4 feet (122 cm)

Proportionate dwarfism. Proportionate dwarfism results from medical conditions present at birth or appearing in early childhood that limits overall growth and development.

So the head, trunk, and limbs are all small, but they're proportionate to each other. Because these disorders affect overall growth, many of them result in poor development of one or more body systems.

A common cause of proportionate dwarfism is a deficiency of growth hormone. It occurs when the pituitary gland fails to produce an adequate supply of growth hormone, which is essential for normal childhood growth.

Signs include:

  • Height below the third percentile on standard pediatric growth charts
  • Growth rate slower than expected for age
  • Delayed or no sexual development during the teen years .

3 Causes

In most dwarfism occurs as a result of genetic disorders, however, the cause in some cases is still unknown.

Dwarfism can occur as a result of a random genetic mutation in either the father's sperm or the mother's egg rather than from either parent's complete genetic makeup.

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, a condition that affects only girls and women, results when a sex chromosome (the X chromosome) is missing or partially missing.

A female inherits an X chromosome from each parent. A girl with Turner syndrome has only one fully functioning copy of the female sex chromosome rather than two.

Growth hormone deficiency can also cause dwarfism. 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 other genetic disorders, deficiencies in other hormones or poor nutrition.

4 Making a Diagnosis

Making a diagnosis of dwarfism is done by performing several tests.

Disproportionate dwarfism is usually present  at birth or early in infancy while proportionate dwarfism may not be diagnosed until later in childhood or the teenage years.

Proportionate dwarfism is mostly diagnosed if a child isn't growing at an expected rate.

Annual visits to a pediatrician are important as these visits are an opportunity for the child's doctor to track growth, note delays in expected growth and identify other problems in physical development.  

Pediatricians usually examine a number of factors to assess a child's growth and determine whether he or she has a dwarfism-related disorder.

Diagnostic tests may include:

  • Measurements. A regular part of a well-baby medical exam is the measurement of height, weight, and head circumference. Pediatricians usually plot these measurements on a chart to show a child's current percentile ranking for each one. This is important for identifying abnormal growth, such as delayed growth or a disproportionately large head. If any trends in these charts are a concern, a pediatrician may make more frequent measurements.
  • Appearance. Many distinct facial and skeletal features are associated with each of several dwarfism disorders. A child's appearance also may help your pediatrician to make a diagnosis.
  • Imaging technology. Imaging studies, such as X-rays, because certain abnormalities of the skull and skeleton can be used to indicate which disorder a 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 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. If Turners’s syndrome is suspected, then a special lab test may be done that assesses the X chromosomes extracted from blood cells.
  • Family history may be taken to review a history of stature in siblings, parents, grandparents or other relatives and to help determine whether the average range of height in your family includes short stature.
  • Hormone tests that assess levels of growth hormone or other hormones that are critical for childhood growth and development therapy to develop everyday skills and to use adaptive products that help with everyday activities.

5 Treatment

Most dwarfism treatments don't increase stature. However, treatment may correct or relieve problems caused by complications.

Surgical procedures that may correct problems in people with disproportionate dwarfism include:

  • Correcting the direction in which bones are growing
  • Stabilizing and correcting the shape of the spine
  • Increasing the size of the opening in bones of the spine (vertebrae) to alleviate pressure on the spinal cord
  • Placing a shunt to remove excess fluid around the brain (hydrocephalus), if it occurs
  • Limb lengthening

Some people with dwarfism choose to undergo a surgery called extended limb lengthening. This procedure is controversial for many people with dwarfism because, as with all surgeries, there are risks.

Because of the emotional and physical stress of multiple procedures, waiting until the person with dwarfism is old enough to participate in the decision to have the surgery is recommended.

Hormone therapy may be recommended for individuals with dwarfism that occurs due to growth hormone deficiency.

In most cases, children receive daily injections for several years until they reach a maximum adult height — often within the average adult range for their family.

Treatment may continue throughout the teen years and early adulthood to ensure adult maturation, such as appropriate gain in muscle or fat. Some individuals may need lifelong therapy.

The treatment may be supplemented with other related hormones if they are also deficient.

Treatment for girls with Turner syndrome also requires estrogen and related hormone therapy in order for them to begin puberty and achieve adult sexual development.

Estrogen replacement therapy usually continues throughout life until a woman reaches the average age of menopause.

It is important to note that growth hormone supplements for children with achondroplasia does not increase final adult height.

Regular checkups and ongoing care by a doctor familiar with dwarfism can improve the quality of life.

Because of the range of symptoms and complications, treatments are tailored to address problems as they occur, such as assessment and treatment for ear infections, spinal stenosis or sleep apnea.

Adults with dwarfism should continue to be monitored and treated for problems that occur throughout life.

6 Lifestyle and Coping

People with dwarfism can cope with challenges and function independently by:

  • Seeking help from nonprofit organization Little People of America for social support, information about disorders, advocacy opportunities, and resources.
  • Making changes in the home, such as putting specially designed extensions on light switches, installing lower handrails in the stairways and placing doorknobs with levers.
  • Having personal adaptive tools to help with every activity and self-care.

7 Risks and Complications

Complications of dwarfism-related disorders depend on the type of dwarfism.

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 and risk of hearing loss.
  • Bowing of the legs.
  • Difficulty breathing during sleep (sleep apnea).
  • Pressure on the spinal cord at the base of the skull
  • Excess fluid around the brain (hydrocephalus).
  • Crowded teeth.
  • Progressive severe hunching or swaying of the back with back pain or problems breathing.
  • Narrowing of the channel in the lower spine (spinal stenosis), resulting in pressure on the spinal cord and subsequent pain or numbness in the legs.
  • Arthritis.
  • Weight gain that can further complicate problems with joints and the spine and place pressure on nerves.

Proportionate dwarfism. With proportionate dwarfism, problems in growth and development often result in complications with poorly developed organs.

 An absence of sexual maturation associated with growth hormone deficiency or Turner syndrome affects both physical development and social functioning.

Women with disproportionate dwarfism may develop respiratory problems during pregnancy. A C-section (cesarean delivery) is almost always necessary because the size and shape of the pelvis don't allow for successful vaginal delivery.

Most people with dwarfism prefer not to be labeled by a condition. However, some people may refer to themselves as dwarfs or little people.

The word "midget" is generally considered an offensive term. People of average height may have misconceptions about people with dwarfism.

And the portrayal of people with dwarfism in modern movies often includes stereotypes. Misconceptions can impact a person's self-esteem and limit opportunities for success in school or employment.

Children with dwarfism are particularly vulnerable to teasing and ridicule from classmates. Children may feel isolated from their peers because dwarfism is relatively uncommon.

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