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:
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 — other than short stature — vary greatly across the range of dwarfism conditions.
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:
Another cause of disproportionate dwarfism is a rare condition called spondyloepiphyseal dysplasia congenita (SEDC).
Signs may include:
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:
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.
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.
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, 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.
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 of dwarfism include other genetic conditions, low levels of other hormones, or poor nutrition. Sometimes the cause is not known.
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 of dwarfism-related conditions can vary greatly, but some complications are common to several conditions.
The typical features of the skull, spine and limbs shared by most forms of disproportionate dwarfism result in some common complications:
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.
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.
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.
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:
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:
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.
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.
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.
Surgical procedures that may correct problems in people with disproportionate dwarfism include:
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.
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.
Talk with your pediatrician or a specialist about at-home care. Issues critical for children with disproportionate dwarfism include:
If your child has dwarfism, you can take several steps to help them cope with challenges and do what they need to do independently:
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.
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:
If your family healthcare professional or pediatrician thinks that your child shows signs of dwarfism, you may want to ask these questions:
Preparing for these questions can help you make the most of your appointment time.
