Key takeaways

  • Dwarfism refers to medical or genetic conditions that result in an adult height of 4 feet 10 inches or shorter.
  • Most cases result from genetic disorders, particularly achondroplasia, which accounts for roughly 70% of cases and occurs from a spontaneous gene mutation in 4 out of 5 cases.
  • Management may include growth hormone injections for hormone deficiency, surgeries to address complications like spinal stenosis or hydrocephalus, and physical therapy or orthotics to support mobility and function.

“Dwarfism” refers to medical or genetic conditions that cause someone to be considerably shorter than average.

While the average height of an adult with dwarfism is 4 feet (ft), the advocacy group Little People of America (LPA) defines “dwarfism” as any condition that leads to an adult height of 4 ft 10 inches (in) or shorter.

In this article, we offer a broad overview of dwarfism, discussing the types of dwarfism, causes, complications, management, and more.

There are many different types of dwarfism. According to the LPA, there are roughly 400 types. The different types of dwarfism are often grouped into two main categories: disproportionate and proportionate.

Disproportionate dwarfism

Disproportionate dwarfism is the most common kind of dwarfism. It involves having body parts — namely the head, limbs, and torso — that are disproportionate to one another.

For example, a genetic condition called achondroplasia results in having proportionally short arms and legs and a torso of typical size.

Other types of disproportionate dwarfism include:

  • spondyloepiphyseal dysplasia congenita (SEDc)
  • diastrophic dysplasia
  • pseudoachondroplasia

Proportionate dwarfism

A condition is considered proportionate dwarfism when a person’s head, trunk, and limbs grow in proportion to one another despite their overall height being shorter than average.

There are various medical and genetic causes of proportionate dwarfism, including:

  • growth hormone (GH) deficiency
  • chronic illness
  • malnutrition

The different types of dwarfism have a range of potential causes, including genetic disorders, endocrine disorders, bone diseases, malnutrition, and other systemic disorders.

Genetic disorders

Genetic disorders are responsible for most cases of dwarfism. They may involve random genetic mutations or inheritance.

The most common type of dwarfism is achondroplasia, which accounts for roughly 70% of dwarfism cases. Achondroplasia results from a mutation in a gene involved in bone growth.

Other genetic disorders linked to short stature include Turner syndrome, Prader-Willi syndrome, and Down syndrome.

Endocrine disorders

Your endocrine system is responsible for producing hormones that regulate bodily functions such as growth and metabolism. Certain disorders that affect hormone production can result in short stature.

Dwarfism is usually the result of a genetic mutation. But having a gene or genes responsible for dwarfism can occur in a couple of ways.

Gene mutations don’t need to be inherited from a parent. In many cases, they can happen spontaneously without an identifiable cause. In 4 out of 5 cases of achondroplasia, the genetic mutation causing the condition occurs spontaneously with no family history.

Inherited genetic disorders can take two forms. One is recessive, which means you inherit two mutated genes (one from each parent) to have the condition. The other is dominant, where you only need one mutated gene — from either parent — to have the disorder.

Other risk factors for dwarfism include a hormone deficiency or malnutrition. There usually aren’t any risk factors for a hormone deficiency, but it can often be successfully treated.

Serious malnutrition, which leads to weak bones and muscles, can also be overcome in many cases with a healthy, more nutrient-rich diet.

A physical exam at birth may be enough to diagnose dwarfism in a newborn. In addition to physical exams, healthcare professionals may use genetic tests, blood tests, or X-rays to make a diagnosis.

In some cases, healthcare professionals can use ultrasound imaging to make a prenatal diagnosis while the baby is still in the womb. If the baby’s appearance suggests dwarfism, or if the parents know they carry a gene for dwarfism, a doctor may recommend amniocentesis. This is a lab test of amniotic fluid from the womb.

Genetic testing may be helpful in some cases. This is particularly true when distinguishing one potential cause of dwarfism from another.

A blood test to check for growth hormone levels may also help confirm a diagnosis of dwarfism caused by hormone deficiency.

Dwarfism is often accompanied by health complications. These range from leg and back problems to brain and lung function issues. The specific complications you may experience vary based on the underlying cause of your dwarfism.

Common complications associated with disproportionate dwarfism include:

Pregnancy in those with dwarfism can present its own set of potential complications, including respiratory problems. A cesarean delivery is usually necessary because the size of the pelvic region won’t allow for a vaginal delivery.

For some people with proportionate dwarfism, poor development of the organs can lead to significant health problems.

Most forms of dwarfism have no cure. For these conditions, management focuses on reducing the risk of complications and promoting growth.

Hormone therapy

For people with growth hormone deficiency, injections of synthetic human growth hormone may be helpful. Children receiving this treatment don’t always reach an average height, but they can get close.

The treatment includes daily injections when a child is young, though injections may continue into a person’s 20s. This may be done if there are concerns about full adult maturation and sufficient muscle and fat.

Surgical options

For others with dwarfism, surgical treatments may be necessary and helpful to living a longer, healthier life. Doctors may recommend surgery to address complications.

Surgical treatments include those that can help:

  • correct the direction of bone growth
  • stabilize the spine
  • increase the channel in the vertebrae surrounding the spinal cord to relieve pressure on the spinal cord

Another surgical procedure for people with excess fluid around the brain is to place a type of tube, called a shunt, in the brain. This can relieve some of that fluid and reduce pressure on the brain.

Physical therapy and orthotics

Physical therapy and orthotics are noninvasive solutions to some complications of dwarfism. Physical therapy is often prescribed after limb or back surgery to help you regain or improve your range of motion and strength.

Physical therapy may also be advised if dwarfism is affecting the way you walk or is causing you pain that doesn’t require surgery.

Orthotics are custom-made devices that fit into your shoes to help improve your foot health and function. If dwarfism is affecting your balance, how you walk, or other aspects of foot function, talk with a podiatrist about how orthotics may help you.

Medication

In recent years, the Food and Drug Administration (FDA) has approved medications specifically for the treatment of achondroplasia. These drugs — vosoritide and navepedgritide — have both been shown to promote linear bone growth.

Organizations such as LPA provide resources to help with the emotional and logistical challenges of life with dwarfism. Finding a support group can help you connect with a community of people who have had similar experiences.

The LPA can also help you learn about how to lower light switches, doorknobs, and other things in your home. They can also provide information and resources about special tools or equipment you can use and modifications you can make to your car, school, or workspace.

For children with dwarfism, the challenges can be especially difficult. Teasing, bullying, and even innocent misunderstandings about the condition can be troublesome.

If you have a child with dwarfism, talk with teachers and others at their school to help them understand the condition and how they might educate others about it. You may also need to talk with your school about tools and other accommodations that will be helpful or necessary for your child.

You should also encourage your child to talk about their feelings or other concerns.

Can I pass the condition on?

When it comes to having a family, there are some important considerations. When both parents have dwarfism, the odds of a child being born with dwarfism are higher than in the general population.

If you have achondroplasia, for example, you have one dwarfism gene and one unaffected gene. This means when both parents have achondroplasia, there is a 25% chance their child will inherit the unaffected gene and grow to at least an average height.

There is a 50% chance of the child inheriting one of each type of gene, but a 25% chance that the baby will have two dwarfism genes. Babies born with what is called a “double-dominant syndrome” often die at birth or soon afterward.

People with dwarfism often live long, fulfilling lives. The condition doesn’t affect the ability to go to school or work, have a family, or enjoy any of the other things life can offer.

However, dwarfism can lead to potentially serious medical complications. It’s important to keep up with annual physicals and visits to specialists as needed. Being proactive about your health and responding quickly to changes in your symptoms is crucial.