Dwarfism may be defined as significantly short stature as an adult. There are hundreds of different conditions that can cause dwarfism. The vast majority of people with dwarfism have normal intelligence and can expect to live full life spans. Though people with dwarfism are protected from discrimination under the Americans with Disabilities Act, many do not consider themselves disabled. Most types of dwarfism neither have nor require a cure.

Skeletal dysplasias (conditions of abnormal bone growth) are the most common forms of dwarfism. They are divided into two types: short-limb and short-trunk dysplasias. These conditions affect bone and cartilage growth and result in unusually short stature and body parts (e.g., arms, legs) that are disproportionate in length in comparison to the rest of the body. Achondroplasia is the most common form of dwarfism. People with this type of skeletal dysplasia have a relatively long trunk with short upper arms, thighs, fingers and toes. Many other conditions, including hormonal problems during childhood, can also result in dwarfism.

Many infants and children with dwarfism, particularly those with skeletal dysplasias, do not learn motor skills (e.g., sitting up, walking) as early as other children their age. However, cognitive (mental) delays are not usually present. When a child with dwarfism begins to walk, he or she may have a waddling walk and may be bowlegged or knock-kneed. Spinal problems (e.g., humpback, swayback, scoliosis) may also occur.

Self-esteem and a sense of independence are best established early. It is important to regard dwarfism, especially skeletal dysplasias, as a physiological difference rather than a problem. This outlook is important for both the child and the people with whom the child socializes.

Certain forms of dwarfism are genetic. In some cases, a person with dwarfism has one dwarfism gene, which can be inherited from either parent. However, most children born with dwarfism do not have parents with the condition. Many forms of dwarfism are usually the result of a spontaneous mutation in a single gene in either a sperm or egg cell from average-sized parents. It is not known why this occurs, but it may happen in any pregnancy.

Some forms of dwarfism can be identified prenatally. This may be done through a series of ultrasounds or through karyotypes (tests that allow physicians to evaluate the fetus’s genes). Other cases of dwarfism are discovered immediately after the child is born. Hormonal problems, such as growth hormone deficiency, are frequently the cause of dwarfism that is not discovered until the child is older.

Growth charts are important in the diagnosis of dwarfism. These measure a child’s growth rate and allow it to be compared to those of thousands of children throughout the country. There are special growth charts for children with many conditions that cause dwarfism, including achondroplasia.

Dwarfism is typically defined as any condition that generally leads to a very short adult height. What height constitutes “very short” depends on the average for a given population, as defined by gender, race and ethnicity. In general, there are a wide variety of statures that are normal for a given population. A person in the shortest 3 percent of that population may be diagnosed with dwarfism.

Hormones are responsible for growth and development. Glands in the endocrine system produce these hormones and secrete them into the bloodstream, which distributes them throughout the body. The pituitary gland is particularly important for growth. This small gland at the base of the brain is controlled by the part of the brain called the hypothalamus. It produces pituitary hormones, which are responsible for controlling growth and development. Among the most important of these is a hormone called growth hormone. 

However, the pituitary gland is not the only important part of the endocrine system. The thyroid gland produces hormones that help support normal growth. Other important endocrine system hormones include androgens (estrogen and testosterone). These hormones are involved in sexual development and function, but are important for many bodily functions including growth, particularly during puberty.

There are three primary phases of growth. The infantile phase covers the first two years of life. During this phase growth is initially very rapid, although it slows down over time. Most infants grow about 11.8 to 13.8 inches (about 30 to 35 centimeters) during this phase. The childhood phase covers the period after 2 years of age until puberty. It is characterized by a generally constant growth rate of about 2.0 to 2.8 inches (around 5 to 7 centimeters) per year, although this rate often slows down in later childhood. The pubertal phase covers the growth spurts that occur between the onset of puberty until adulthood. It has the most variation in growth patterns from one person to another. During this phase, adolescents typically grow around 3.5 to 5.5 inches (about 8 to 14 centimeters) per year. This accelerated growth rate is caused by the increased release of androgens and growth hormone.

Normal growth and height is determined by population averages. These averages usually take gender, race and ethnicity into consideration. The average height of men is taller than the average height of women. Furthermore, some races and ethnic groups are significantly taller or shorter than others. There is a very wide range of what is normal in all populations. Only the shortest and tallest 3 percent of a population are considered to have abnormal height.

The only feature that all people with dwarfism share is their significantly short stature. Hundreds of conditions can result in dwarfism, and every one has its own unique features. By far the most common form of dwarfism is achondroplasia, a type of skeletal dysplasia caused by abnormal bone and cartilage growth. This condition results in arms and legs that are disproportionately short in comparison to the rest of the body. Some forms of dwarfism result in more usual arm, leg and body proportions. Most of these forms of dwarfism are caused by problems with hormones, especially growth hormone.

The vast majority of people with dwarfism have normal intelligence and can expect to live full life spans. However, some forms of dwarfism are associated with mental retardation and learning disabilities, and some are fatal in infancy. Other forms may be associated with potentially fatal complications. Although people with dwarfism are protected from discrimination under the Americans with Disabilities Act, many do not consider themselves disabled. Most types of dwarfism neither have nor require a cure.

The hundreds of conditions that can cause dwarfism have unique potential complications. Many of these complications are reversible or treatable, particularly when detected and corrected early in life. Some common complications include:

• Hydrocephalus. Too much fluid around the brain. This is very common, especially in achondroplasia. It occurs because the drainage openings in the skull are too small to allow proper drainage. Hydrocephalus does not usually cause any long-term problems. However, if problems do result, surgery to implant a shunt can improve drainage.
  
  
• Apnea. Interruptions in breathing during sleep. It may be caused by obstruction by the adenoids or tonsils, small or misshapen airways, or the compression of the brain stem or spinal cord. Many children with apnea outgrow it as they age. It can be treated by monitoring the child’s breathing and possibly supplementing oxygen, removing the adenoids (adenoidectomy) or tonsils (tonsillectomy), or surgery to relieve compression of the brain stem or spinal cord. Rarely, a temporary tracheostomy (a surgical opening into the windpipe) may be used.
  
  
• Eye and ear problems. Many forms of dwarfism are associated with eye and ear problems, including vision and hearing loss. Frequent ear infections may also be common.
  
  
• Early wear and tear on bones and joints. This is particularly common in people with disproportionate dwarfism. It often results in early arthritis. It is generally caused by extra stress due to improper weight dispersal, limited flexibility of the joints and by certain changes in collagen proteins. Surgery, maintaining a proper weight and physical therapy may be used in treatment and prevention.
  
  
• Compression of the brain stem and spinal cord. The openings in the skull and spinal column may be too small to accommodate the brain stem and spinal cord, compressing them. This can be corrected through surgery to enlarge the openings.

Dwarfism may cause lifestyle management issues that are not health-related. Many common safety features, particularly those in automobiles (e.g., car safety belts, airbags) are developed for adults of average height. They may not function properly for patients with dwarfism and, in some cases, may actually be dangerous. Talking with a physician or physical therapist can help patients and their families identify these safety problems. Contacting dwarfism advocacy groups may also be beneficial.

Athletics may also be a concern. Forms of exercise that place excessive stress on the bones and joints (especially the spine) can be dangerous for patients with certain forms of dwarfism. These exercises include long-distance running and extensive walking. Other forms of exercise, such as swimming and bicycling, may be used as an alternative. However, in general, normal childhood play is safe for healthy children with dwarfism who have no unusual problems with their bones or joints.

Researchers have expressed concern over the affect that dwarfism may have on a child’s self-esteem, body image and social interactions. However, some studies have demonstrated that patients with dwarfism fare better in all of these areas than previously suspected. It is still very important to promote a strong degree of self-esteem in people with dwarfism and to educate the child and people in the child’s social environment about dwarfism.

There are hundreds of conditions that can lead to dwarfism, each with its own distinct features. The characteristic these types of dwarfism have in common is a significantly short adult height compared to the average.

Many children who seem much shorter than their peers at particular ages do not actually have dwarfism. Many of these children will eventually reach a normal adult height. In some stages of development, particularly in adolescence, there is an extremely wide range of normal growth. As long as the child’s growth remains steady overall, a normal, if slightly below average, final adult height can be expected.

With more than 200 different types, skeletal dysplasias are the most common forms of dwarfism. These conditions affect bone and cartilage growth and typically result in disproportionate short stature. This means that the body parts are not in usual proportions. There are special growth charts available to monitor the growth of children with skeletal dysplasias. There are two general types:

• Short-trunk dysplasias. Characterized by a shorter trunk with proportionately longer arms and legs. Arms and legs may still be shorter than normal, but they seem long for overall body size.
  
  
• Short-limb dysplasias. Normal-sized trunk and normal-sized or large head with short arms and legs.

The most common types of skeletal dysplasias include:

• Achondroplasia. This short-limb dysplasia is the most common type of dwarfism. According to the March of Dimes, achondroplasia accounts for about 70 percent of all cases of dwarfism. This condition is apparent at birth. The average final adult height of patients with achondroplasia is around 4 feet (about 122 centimeters).
  
  People with this condition have a relatively long trunk with short upper arms, thighs, fingers and toes. They often have a large head with a prominent forehead. They may also have a small midface with a flat nasal bridge and narrow nasal passages. They tend to have a small, prominent jaw and may have crowded teeth. Reduced muscle tone is common.
  
  
• Spondyloepiphyseal dysplasias (SEDs). This is a group of several closely related short-trunk dysplasias that affect about one in 95,000 babies. They involve changes in collagen proteins (parts of bone, cartilage and connective tissues). Some forms are apparent at birth whereas others may not be diagnosed until the child is five to 10 years old. The adult final height of patients with SEDs is usually between about 2 feet, 10 inches and 4 feet, 4 inches (85 to 130 centimeters).
  
  Common features in some children with SEDs include clubfeet, a flat face with widely spaced eyes, a broad or barrel-shaped chest, normal hands and feet and a swayback. Many children have a short neck, and the head may seem to be placed directly on the shoulders. This is more apparent as the child gets older. SEDs are also commonly associated with cleft palate, a waddling, wide-based walk and eye problems (e.g., vision loss, retinal detachment) and deafness.
  
  
• Diastrophic dysplasia. This form of short-limb dwarfism is more common in Finland than in other world populations. Patients with diastrophic dysplasia tend to reach a final adult height of between about 2 feet, 10 inches and 4 feet, 3 inches (around 86 and 127 centimeters). The risk of potentially fatal respiratory complications is higher in infants with this condition due to abnormalities in cartilage formation. However, if infancy is survived, a normal lifespan can be expected.
  
  Patients with diastrophic dysplasia have shortened forearms and calves. They often have short, broad fingers, thumbs that curve backwards (hitchhiker thumb), clubfeet and cleft palate. Their ears tend to swell just after birth. The swelling subsides after a few days, but the ears may develop a cauliflower-like appearance. These patients may have frequent bone and joint problems, including easily dislocated joints (e.g., shoulder, elbows, hips, knee caps) and joints that will not fully extend (joint contractures). Scoliosis (a sideways curve of the spine) and a hunchback (kyphosis) are also common.

Some other forms of skeletal dysplasias are life-threatening. Infants with these conditions are often stillborn or die shortly after birth. One example of these lethal forms of dwarfism is achondrogenesis. This condition is characterized by extremely short limbs, large heads and low birthweight.

Metabolic or hormonal disorders that may result in dwarfism tend to cause proportionate dwarfism. All body parts are shortened, but they remain in more usual proportions. These disorders may be easy to treat. They include:

• Hypothyroidism. Inadequate production of thyroid hormones. The failure to grow at a normal rate may be the only sign of this condition.
  
  
• Hypopituitarism. Inadequate production of pituitary hormones. This includes growth hormone deficiency. Not all forms of hypopituitarism result in dwarfism. Children can be born with the problem or develop it later. It is frequently associated with a delay in or absence of pubertal development.
  
  
• Growth hormone deficiency. Occurs when the pituitary gland does not produce enough growth hormone. It is a rare condition and may range from mild to severe. The causes can be difficult to impossible to detect. Growth hormone deficiency results in failure to grow and the delayed maturation of the bones.
  
  
• Laron syndrome. Also called growth hormone insensitivity. This occurs when the body cannot access the growth hormone that the pituitary gland produces. It is a rare condition.
  
  
• Hall-Pallister syndrome. The absence of a pituitary gland. This rare condition results in numerous problems, including dwarfism, the presence of too many fingers or toes, nail problems, bifid epiglottis (splitting of the flap of tissue that keeps food from entering the windpipe), imperforate anus (anus that does not properly open) and problems with the heart, lung and kidneys.

Several forms of dwarfism (e.g., some spondyloepiphyseal dysplasias, growth hormone deficiencies) are not noticeable in infancy. However, some of the most common, including achondroplasia, are apparent at birth. While each of these conditions has its own distinct features, there are some factors that are common.

Motor delays may be present in infants with skeletal dysplasias, but generally first become apparent in childhood. Middle ear infections (otitis media) are common. They may be due to small nasal passages and Eustachian (auditory) tube problems. These infections can lead to hearing loss if they are not treated. The opening in the base of the skull may be narrow. This can result in the compression of the brain and spinal cord (foramen magnum compression). This may cause sleep apnea (interruptions in breathing while asleep) and other problems. It can be treated by surgery to increase the size of this opening. All infants with certain forms of dwarfism (e.g., achondroplasia) must be monitored for this condition.

Many forms of dwarfism that are not obvious in infancy become apparent in early childhood. Hormonal types of dwarfism, in particular, are frequently not noticed until this developmental stage. Cognitive (mental) delays are not usually present, but motor delays may be noticed. Many children, particularly those with skeletal dysplasias, may not begin walking as soon as other children of a similar age. These children may be knock-kneed or bowlegged when they begin to walk. Often, a child who is knock-kneed will initially become bow-legged as walking becomes more frequent. There may be some pain in the lower back and legs.

Before children with skeletal dysplasias begin to walk, they may have a humpback spinal position when sitting up. Child furniture (e.g., swings, walkers) with full back support helps to prevent this from occurring or getting worse. Once the child begins walking, the humpback will often shift into a swayback. Scoliosis (sideways curvature of the spine) may also occur and spinal bracing may be necessary. Early arthritis is common and the child’s joints may not be properly flexible.

Children with skeletal dysplasias may have breathing problems due to small chests or obstruction of small airways. This can result in snoring, sleep apnea (interruptions in breathing while asleep), and holding the neck in an overly stretched position when sleeping. Breathing problems may be diagnosed by a sleep study. If the tonsils or adenoids are obstructing the child’s airways, they may be surgically removed (with a tonsillectomy or adenoidectomy).

Some forms of dwarfism (e.g., spondyloepiphyseal dysplasias) cause patients to be predisposed to vision and/or hearing problems. It is important for these children to maintain regular vision and hearing exams.

It is important to look at dwarfism, especially skeletal dysplasias, as a variation in human growth patterns rather than a problem. Such an attitude needs to be maintained both with the child and others. Parents of children with dwarfism may need to talk to teachers and school administrators to ensure that the same attitude is maintained at school. It is important to encourage activities or hobbies that are best suited to the child. Many physical activities (e.g., certain sports) may not be best, but there are numerous other activities that the child’s size will not affect (e.g., writing, swimming, drawing, music). Self-esteem and a sense of independence are best established early.

Other tips that can help build and maintain a child’s self-esteem and sense of independence include:

• Avoid making exceptions. Children with dwarfism do not need to be treated any differently than other children the same age. It is important to require the same contribution to the household (e.g., chores) that would be required for other children.
  
  
• Adjust to the child’s height. Make simple changes to help the child function. Items that the child may need or want to use (e.g., bathroom supplies including extended wands for wiping, children’s silverware and dishes) can be placed in lower drawers and cabinets. Light switch extenders and lower-set furniture can help a child to be more independent.
  
  
• Keep in contact with others. Meeting other people with dwarfism may help the child. Many associations, such as the March of Dimes, are available for information and support.

A common problem for adolescents with some forms of dwarfism, particularly achondroplasia and other skeletal dysplasias, is spinal stenosis. In this condition, the opening of the spinal column is not big enough for the spinal cord, so the spinal cord is compressed. Symptoms include weakness and tingling and pain in the legs that may be relieved by a squatting position. These symptoms tend to develop during adolescence or early adulthood. The pain often progresses into the lower back and buttocks over time. It is treated with a laminectomy, which is a surgical procedure that increases the size of the opening in the vertebra.

Hundreds of distinct conditions result in dwarfism. The only thing all patients have in common is significantly short stature compared to the average.

Skeletal dysplasias are the most common forms of dwarfism. These are characterized by abnormal body proportions. Typically, the arms and legs are too short in proportion with the rest of the body. However, sometimes the rest of the body may appear to be too short for the arms and legs. Other problems associated with many skeletal dysplasias include problems with the bones and joints, particularly the spine and legs. Poor muscle tone and a waddling walk are common. Many children with skeletal dysplasias also have a high-pitched voice that does not deepen following puberty.

Some forms of dwarfism can be identified prenatally. This may be done through a series of ultrasounds or through karyotypes (tests that allow physicians to evaluate the fetus’ genes). Other cases of dwarfism are discovered immediately after the child is born. Dwarfism that is not discovered until the child is older may be due to hormonal problems, such as growth hormone deficiency. When children do not appear to be growing normally, they are often referred to an endocrinologist (physician who specializes in the endocrine system).

An evaluation of a child who may have dwarfism begins with a physical examination. The child’s physical appearance alone may be enough to diagnose dwarfism, at least in a general sense. Other tests may be necessary to determine which type of dwarfism is present. The physical examination often includes measurements of body proportions, such as measuring the child’s arm span or upper-to-lower body ratio. Diagnosis will include which long bones are most affected.

An evaluation of the child’s family history is also important. This can help differentiate actual dwarfism from short stature in childhood or adolescence that result in a normal final adult height. Most children with these conditions have parents who had similar growth patterns. Many forms of dwarfism are hereditary, as well.

Growth charts are important in the diagnosis of dwarfism. For any child, height and weight are measured at every well-child visit and charted on a graph. This chart demonstrates a growth curve that measures the child’s rate of growth. The overall curve is typically more important than the child’s height or weight at any given check-up. This ensures that the child is growing at a steady, consistent and predictable rate. A child’s growth chart can be compared to similar graphs of thousands of children all over the country. This allows the pediatrician to determine if the child is growing in a normal range. There are special growth charts for children with many types of skeletal dysplasias, including achondroplasia, spondyloepiphyseal dysplasias and diastrophic dysplasia. There are also special growth charts for many other conditions commonly associated with short stature, including Down syndrome.

Several diagnostic tests can help physicians determine if a child may have dwarfism and diagnose the potential cause. Blood tests are important for diagnosing hormonal causes of dwarfism. They may also be used to develop a karyotype, which can be useful in the diagnosis of genetic causes. A urinalysis may be used to check for kidney problems and fecal tests may be used to determine if a child’s failure to grow is due to a digestive system problem.

Imaging tests may also be used. X-rays can help to determine if bone growth is delayed. Several tests, including x-rays, ultrasounds, CAT scans and magnetic resonance imaging (MRI) may be used to evaluate potential complications, including hydrocephalus (excess fluid around the brain) and spinal stenosis (compression of the spinal cord).

Most forms of dwarfism cannot be treated or cured. This is especially true for skeletal dysplasias. However, any complications that may result from the conditions can be treated. Dwarfism that results from hormonal or metabolic conditions can often be treated using hormone injections.

Growth hormone treatment involves a synthetic growth hormone that is provided as a daily injection. It is used to treat short stature due to growth hormone deficiency, Laron syndrome, Turner syndrome and Prader-Willi syndrome. It may also be used to improve growth in children with other conditions that lead to a significantly short final adult height.

Treatment with growth hormone lasts for many years and is most effective when begun early. The results may not be noticed for weeks or months, but are most pronounced in the first year of treatment. For children with growth hormone deficiency, growth rates tend to increase two- to five-fold during the first year of treatment. Following this, the growth rate slows down but still tends to remain above what it would be without treatment. Growth hormone treatment continues until the bones are fully mature and growth no longer continues, which can be determined by x-ray. The final effect of treatment depends on how long treatment occurred.

Growth hormone treatment is most beneficial for children with growth hormone deficiency. For other conditions, the child’s final adult height may be increased by 2 to 3 inches (about 5.0 to 7.6 centimeters). For example, the final adult height of girls with Turner syndrome who undergo this treatment is increased by an average of about 2.4 inches (about 6.0 centimeters). However, some children experience much less growth. There is currently no way to determine which children will benefit most from growth hormone injections.

Growth hormone treatments are not without disadvantages. They can be quite expensive, and because they may not be effective in some children the cost may not be worth the increased growth rate. Reversible hypothyroidism (not enough thyroid hormone) may occur during treatment. Because of this side effect, children receiving growth hormone injections require regular blood tests to monitor thyroid function. Skeletal and joint problems may also be linked to growth hormone treatment. Children on this treatment who experience hip or knee pain require a thorough examination. This form of treatment may also cause an increased risk of developing leukemia (cancer of the blood and bone marrow). However, it is unclear whether growth hormone treatment is the cause of the risk. It may be due, instead, to other treatments and tests that often occur along with growth hormone treatments, such as radiation therapy and chemotherapy for tumors.

If there are any other hormonal deficiencies, they also need to be treated. Pituitary hormones have many functions other than growth. Since hypopituitarism tends to include both growth hormone deficiency and other hormonal deficiencies, children may need to receive multiple replacement hormones. If hypothyroidism is present, thyroid medications may be used. Proper nutrition is also vital for growth. A nutritionist can help establish the best diet for a particular child.

Short stature due to child abuse may require the assistance of a mental health professional. Many states have laws that require anyone who suspects child abuse to report it. If a child with dwarfism experiences any additional stress or concerns about his or her size and condition, talking to a mental health professional can help in maintaining a positive attitude.

Some causes of dwarfism are genetic. There are no ways to actively prevent them. Genetic counseling can help prospective parents with dwarfism determine their child’s risk of also having the condition. However, most cases are due to a spontaneous mutation in a gene in an egg or sperm from a parent with no family history of dwarfism. These mutations are not well understood. They seem to be completely random, unpredictable and unpreventable. They can occur in any pregnancy. Recent studies suggest that advanced age in the father may increase this risk.

Preparing questions in advance can help patients and parents to have more meaningful discussions with physicians regarding their or their child’s treatment options. The following questions related to dwarfism may be helpful:

1. What type of dwarfism does my child have?
   
   
2. What are the characteristics of my child’s type of dwarfism?
   
   
3. Does my child require any kind of special care due to dwarfism? If so, what?
   
   
4. What are the potential complications that may occur with my child’s dwarfism?
   
   
5. Are you experienced in recognizing and treating any potential complications of my child’s dwarfism?
   
   
6. Should I expect any particular delays in my child’s development due to his/her dwarfism?
   
   
7. What modifications can I make around the house to accommodate my child’s dwarfism?
   
   
8. What safety features, such as in a car, may not be appropriate for my child? What can I do to ensure my child’s safety?
   
   
9. How should I go about speaking with my child’s teachers and/or daycare providers about my child’s dwarfism?
   
   
10. Are my other children more likely to have dwarfism?
    
    
11. Do you know of any local groups through which I could meet and speak with people who have dwarfism?