Dwarfism

Overview

Dwarfism is short stature that results from a genetic or medical condition. Stature is the height of a person in a standing position. Dwarfism generally is defined as an adult height of 4 feet, 10 inches (147 cm) or less. The average adult height among people with dwarfism is 4 feet, 1 inch (125 cm) for women and 4 feet, 4 inches (132 cm) for men.

Many medical conditions cause dwarfism. In general, dwarfism is divided into two broad categories:

• Disproportionate dwarfism. This is when some parts of the body are small, and others are of average or above-average size. Conditions causing this category of dwarfism get in the way of bone development.
• Proportionate dwarfism. This is when all parts of the body are small to the same degree and appear like a body of average stature. Medical conditions present at birth or that occur in early childhood limit overall growth and development.

Some people prefer the term "short stature" or "little people" rather than "dwarf" or "dwarfism." It's important to be sensitive to the preference of someone who has this condition. Short stature conditions don't include familial short stature — short height that's thought of as a typical variation with typical bone development.

Symptoms

Symptoms — other than short stature — vary greatly across the range of dwarfism conditions.

Disproportionate dwarfism

Most people with dwarfism have conditions that cause short stature with body parts that aren't the same size as one another. Usually, this means that a person has an average-sized trunk and very short limbs. But some people may have a very short trunk and short limbs. Those limbs are larger than the rest of the body. In these people, the head is large compared with the body.

Almost all people with disproportionate dwarfism have average intelligence. Rare exceptions are usually due to a secondary factor, such as excess fluid around the brain. This also is known as hydrocephalus.

The most common cause of dwarfism is a condition called achondroplasia, which causes disproportionately short stature. This condition usually results in:

• An average-sized 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 large head in relation to the rest of the body, with a prominent forehead and a flattened bridge of the nose.
• Bowed legs that get worse.
• Swayed lower back that gets worse.
• An adult height of 4 feet, 1 inch (125 cm) for women and 4 feet 4 inches (132 cm) for men.

Another cause of disproportionate dwarfism is a rare condition called spondyloepiphyseal dysplasia congenita (SEDC).

Signs may include:

• A very short trunk.
• A short neck.
• Shortened arms and legs.
• Average-sized hands and feet.
• A broad, rounded chest.
• Slightly flattened cheekbones.
• An opening in the roof of the mouth, also called a cleft palate.
• Changes in hip structure that result in thighbones turning inward.
• A foot that's twisted or out of shape.
• Neck bones that are not stable.
• Hunching curvature of the upper spine that gets worse over time.
• Swayed lower back that gets worse over time.
• Vision and hearing problems.
• Arthritis and problems moving joints.
• 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 that occur in early childhood that limit overall growth and development. The head, trunk and limbs are all small, but they're small to the same degree. Because these conditions affect overall growth, poor development of one or more body systems is possible.

Growth hormone deficiency is a fairly common cause of proportionate dwarfism. It occurs when the pituitary gland doesn't make enough growth hormone. This hormone is needed for typical 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.

When to see a doctor

Symptoms of disproportionate dwarfism often are present at birth or in early infancy. Proportionate dwarfism may not be seen at first. See your child's healthcare professional if you are worried about your child's growth or overall development.

Causes

Most often dwarfism is caused by gene changes, also called genetic variants. In many children, it's due to a random change in a child's gene. But dwarfism also can be inherited due to a genetic variant in one or both parents. Other causes can include low levels of hormones and poor nutrition. Sometimes the cause of dwarfism is not known.

Achondroplasia

About 80% of people with achondroplasia are born to parents of average height. A person with achondroplasia who had two average-sized parents received one changed gene related to the condition and one regular gene. A person with achondroplasia may pass along a changed gene related to the condition or a regular gene to their children.

Turner syndrome

Turner syndrome, a condition that affects only female children, results when a sex chromosome — the X chromosome — is missing or partially missing. A female child 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.

Low levels of growth hormones

Sometimes low levels of growth hormones can be traced to a genetic change or injury. But for most people with low hormone levels, no cause is found.

Other causes

Other causes of dwarfism include other genetic conditions, low levels of other hormones, or poor nutrition. Sometimes the cause is not known.

Risk factors

Risk factors depend on the type of dwarfism. In many cases, a gene change related to dwarfism happens at random and is not passed from parent to child. If one or both parents have dwarfism, the risk of having a child with dwarfism rises.

If you want to become pregnant and need to understand the chances of your child having dwarfism, talk with your healthcare professional about getting genetic testing. Also ask about other risk factors.

Complications

Complications of dwarfism-related conditions can vary greatly, but some complications are common to several conditions.

Disproportionate dwarfism

The typical features of the skull, spine and limbs shared by most forms of disproportionate dwarfism result in some common complications:

• Delays in developing motor skills, such as sitting up, crawling and walking.
• Ear infections that occur a lot and risk of hearing loss.
• Bowing of the legs.
• A hard time breathing while sleeping, also known as sleep apnea.
• Pressure on the spinal cord at the base of the skull.
• Extra fluid around the brain, also known as hydrocephalus.
• Need for dental work.
• Serious hunching or swaying of the back with back pain or problems breathing that get worse.
• Narrowing of the channel in the lower spine that puts pressure on the spinal cord and leads to pain or numbness in the legs. This is called spinal stenosis.
• Arthritis.
• Weight gain that can complicate joint and spine conditions and place pressure on nerves.

Proportionate dwarfism

With proportionate dwarfism, problems in growth and development often lead to complications with organs that don't grow properly. For example, heart conditions that often occur with Turner syndrome can affect health greatly. An absence of sexual maturation related to having low growth hormone levels or Turner syndrome can affect physical development and social functioning.

Pregnancy

Women with disproportionate dwarfism may have respiratory problems during pregnancy. A C-section is almost always needed because the size and shape of the pelvis doesn't allow for successful vaginal delivery.

Public perceptions

Most people with dwarfism prefer not to be labeled by a condition. But some people may refer to themselves as "dwarfs," "little people" or "people of short stature."

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 affect a person's self-esteem and limit how well they do at school or work.

Children with dwarfism often are teased and mocked by classmates. Because dwarfism is relatively uncommon, children may feel like they're on their own. They may need mental health and peer support for the best quality of life.

Diagnosis

Your pediatrician likely will look at several factors to learn about your child's growth and find out whether your child has a dwarfism-related condition. Your pediatrician may send your child to doctors in other specialties such as endocrinology and genetics. In some cases, disproportionate dwarfism may be suspected during a prenatal ultrasound if very short limbs in relation to the trunk are noted.

Diagnostic tests may include:

• Measurements. A regular part of a well-baby medical exam is the measurement of height, weight and head size. At each visit, your pediatrician plots these measurements on a chart to show your child's current percentile ranking for each one. This is important for identifying growth that isn't typical, such as delayed growth or a large head in relation to the rest of the body. If any trends in these charts are a concern, your child's pediatrician may take measurements more often.
• Appearance. Many distinct facial and skeletal features are related to each of several dwarfism conditions. How your child looks also may help your pediatrician and geneticist make a diagnosis.
• Imaging technology. Your healthcare professional may order imaging studies, such as X-rays, because certain differences in the skull and skeleton can indicate which condition your child may have. Various imaging devices also may reveal delayed maturation of bones, as is the case when growth hormone levels are low. An MRI scan may show if the pituitary gland or hypothalamus is not typical.
• Genetic tests. Genetic tests are available for many genetic causes of dwarfism-related conditions. Your doctor may suggest a test to confirm the diagnosis. This test could help manage the condition and aid in family planning. For example, if your doctor thinks your daughter may have Turner syndrome, a special lab test may be done that looks at the X chromosomes in blood cells.
• Family history. Your pediatrician may ask about the height of your siblings, parents, grandparents or other blood relatives to find out whether the average range of height in your family includes short stature.
• Hormone tests. Your doctor may order tests that measure levels of growth hormone or other hormones that are critical for childhood growth and development.

Health care team

Some conditions that cause dwarfism can cause various problems with development and growth, as well as medical complications. Several specialists may be involved in screening for specific conditions, making diagnoses, recommending treatments and providing care. This team may change as your child's needs change. Your child's pediatrician or family healthcare professional can coordinate the care.

Specialists in your care team may include:

• Hormone disorder specialist (endocrinologist).
• Ear, nose and throat (ENT) specialist (otolaryngologist).
• Specialist in skeletal disorders (orthopedist).
• Specialist in genetic disorders (medical geneticist).
• Heart specialist (cardiologist).
• Eye specialist (ophthalmologist).
• Mental health professional, such as a psychologist or psychiatrist.
• Specialist in conditions of the nervous system (neurologist).
• Dental specialist in correcting problems with teeth alignment (orthodontist).
• Developmental therapist, who specializes in therapy to help your child develop age-appropriate behaviors, social skills and interpersonal skills.
• Occupational therapist, who specializes in therapy to develop everyday skills and to use adaptive products that help with everyday activities.

Treatment

The goal of treatment is to keep you doing what you want to do independently. Most dwarfism treatments don't increase stature, but they may correct or ease problems caused by complications.

Medications

In 2021, the U.S. Food and Drug Administration (FDA) approved vosoritide, known by the brand name Voxzogo, to improve growth in children who have the most common type of dwarfism. Given as a shot, this medicine is for children 5 years of age and older who have achondroplasia and open growth plates so they can still grow. In studies, those who took Voxzogo grew an average of 0.6 inches (1.6 cm). Ask your doctor and geneticist about the potential risks and benefits.

Additional medicines to treat dwarfism are being studied.

Hormone therapy

For people with dwarfism due to low levels of growth hormones, treatment with shots of a synthetic version of the hormone may increase final height. In most cases, children receive daily shots for several years until they reach a maximum adult height — often within the average adult range for their families.

Treatment may continue throughout the teen years and early adulthood to achieve development. Some people may need lifelong therapy. Other related hormones may be added to the treatment if their levels also are low.

Treatment for girls with Turner syndrome also requires estrogen and related hormone therapy to start puberty and lead to adult sexual development. Estrogen replacement therapy usually continues until the average age of menopause.

Giving growth hormones to children with achondroplasia does not increase final average adult height.

Surgery

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

• Correcting the direction the bones grow in.
• Stabilizing and correcting the shape of the spine.
• Increasing the size of the opening in bones of the spine, called vertebrae, to ease pressure on the spinal cord.
• Placing a shunt to remove too much fluid around the brain — also known as hydrocephalus — if it occurs.

Some people with dwarfism choose to undergo surgery called extended limb lengthening. This procedure is controversial because there are risks. Those with dwarfism are urged to wait to decide about limb lengthening until they're old enough to participate in the decision. This approach is recommended because of the emotional and physical stress involved with multiple procedures.

Ongoing health care

Regular checkups and ongoing care by a healthcare professional familiar with dwarfism can make quality of life better. Because there is a range of symptoms and complications, conditions are managed as they happen, such as tests and treatment for ear infections, spinal stenosis or sleep apnea.

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

Lifestyle and home remedies

Talk with your pediatrician or a specialist about at-home care. Issues critical for children with disproportionate dwarfism include:

• Car seats. Use an infant car seat with 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. Stay away from 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.
• Ample head and neck support. Support the head and neck when your child is seated. Hold the head, neck and upper back in a safe and stable position. Padding can help provide the right position and support.
• Complications. Watch your child for signs of complications, such as ear infections or sleep apnea.
• Posture. Promote good posture by providing a pillow for the lower back and a footstool when your child is sitting.
• Healthy diet. Begin healthy eating habits early to stay away from problems with weight gain later.
• Healthy activities. Urge participation in recreational activities that are right for your child as recommended by the healthcare team, such as swimming or bicycling. But stay away from sports that involve collision or impact, such as football, wrestling, diving or gymnastics.

Coping and support

If your child has dwarfism, you can take several steps to help them cope with challenges and do what they need to do independently:

• Seek help. The nonprofit organization Little People of America provides social support, information about conditions, advocacy opportunities and resources. Many people with dwarfism stay involved in this organization throughout their lives.
• Change your home. Make changes to your home, such as putting specially designed extensions on light switches, installing lower handrails in stairways and replacing doorknobs with levers. The Little People of America website provides links to companies that sell adaptive products, such as size-appropriate furniture and everyday household tools.
• Provide personal adaptive tools. Everyday activities and self-care can be a problem with limited arm reach and problems with the use of the hands. The Little People of America website provides links to companies that sell adaptive personal products and clothing. An occupational therapist also may be able to recommend appropriate tools to use at home or school.
• Talk with educators. Talk with teachers and others at your child's school about what dwarfism is. Tell them how it affects your child, what needs your child may have in the classroom and how the school can help meet those needs.
• Talk about teasing. Urge your child to talk with you about feelings. Practice how to respond to insensitive questions and teasing. If your child tells you that bullying happens in school, seek help from your child's teacher, principal or school guidance counselor. Also, ask for a copy of the school's policy on bullying.

Preparing for an appointment

How you learn whether your child has dwarfism depends on how it affects development. Disproportionate dwarfism usually is seen at birth or early in infancy. Proportionate dwarfism may not be diagnosed until later in childhood or the teenage years if your child isn't growing at an expected rate.

Well-baby visits and annual checkups

It's important to take your child to all regularly scheduled well-baby visits and annual appointments throughout childhood. These visits are a chance for your child's healthcare professional to track growth, note delays in expected growth, and find other problems in other areas of development and health.

Questions your child's health professional may ask include:

• What concerns do you have about your child's growth or development?
• How well does your child eat?
• Is your child reaching certain milestones in development, such as rolling over, pushing up, sitting up, crawling, walking or speaking?
• Are other members of the family very short or have others experienced growth delays?
• Do you have your child's height marked on a measuring chart that you brought with you?
• Do you have photographs of your child at various ages that you brought with you?

Talking with the healthcare professional about dwarfism

If your family healthcare professional or pediatrician thinks that your child shows signs of dwarfism, you may want to ask these questions:

• What diagnostic tests are needed?
• When will we learn the results of the tests?
• What specialists should we see?
• How will you screen for conditions or complications that are commonly related to the type of dwarfism affecting my child?
• How will you watch my child's health and development?
• Can you suggest educational materials and local support services for dwarfism?

Preparing for these questions can help you make the most of your appointment time.