What is dwarfism?
Dwarfism is a medical or genetic condition that causes someone to be considerably shorter than an average-sized man or woman. The average height of an adult with dwarfism is 4 feet, but dwarfism could apply to an adult who is 4'10" or shorter.
The term “short stature” is often preferred over “dwarfism” or “dwarf.” The term “little person” or “little people” is often used, too. One of the largest advocacy groups for people with dwarfism is the Little People of America (LPA). “Midget” isn’t an acceptable label.
Be mindful of the words or label a person with dwarfism uses to describe themselves. Also be sensitive to the challenges or prejudice they may face in everyday life.
Types of dwarfism
Though there are many different causes of dwarfism, there are two main types of the condition: proportionate and disproportionate.
When the head, trunk, and limbs are all proportionate to each other, but much smaller than those of an average-sized person, the condition is known as proportionate dwarfism.
This type of dwarfism is often the result of a hormone deficiency. It can often be treated with hormone injections while a child is still growing. As a result, someone born with proportionate dwarfism may be able to reach an average height or get close to it.
This is the most common kind of dwarfism. As the name suggests, it’s characterized by having body parts that are disproportionate to each other. For example, a genetic condition called achondroplasia results in arms and legs that are significantly shorter than those of a person of average size, but the trunk is like that of someone unaffected by dwarfism. In some cases, the head of a person with disproportionate dwarfism may be slightly larger than that of a person without dwarfism.
What causes dwarfism?
Researchers believe there are more than 300 conditions that cause dwarfism. Most causes are genetic. The most common causes include:
Though achondroplasia is a genetic condition, four out of five people who have it also have two parents who are average sized. If you have achondroplasia, you have one mutated gene associated with the condition and one unaffected version of that gene. This is the most common cause of dwarfism.
This condition affects only females. Instead of inheriting two fully functioning X chromosomes from your parents, you inherit one X chromosome and are missing a second, or at least part of a second, X chromosome. Males, by comparison, have an X chromosome and a Y chromosome.
Growth hormone deficiency
The reasons for growth hormone deficiency aren’t always clear. Sometimes it’s tied to a genetic mutation. In many cases, the reasons for growth hormone deficiency are never diagnosed.
An underactive thyroid, especially if it develops at a young age, can lead to many health problems, including limited growth. Other complications include low energy, cognitive problems, and puffy facial features.
A newborn’s thyroid health should be checked as a matter of routine screenings. If your baby didn’t have their thyroid checked, discuss it with your pediatrician.
Intrauterine growth retardation
This condition develops while the baby is still in the mother’s womb. The pregnancy may go to full term, but the baby is usually much smaller than average. The result is typically proportional dwarfism.
Genetics and other risk factors
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.
In some cases, it can happen spontaneously. You may not be born with mutated genes inherited from a parent. Instead, a mutation of your genes happens on its own — usually without a cause doctors can discover.
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. 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.
How is dwarfism diagnosed?
At birth, sometimes the appearance of a newborn may be enough to make a diagnosis of dwarfism. As part of baby wellness exams, your child should be measured and weighed to see how they compare to the population averages for a child their age. Consistently measuring in the lowest quartiles on the standard growth chart is another sign a pediatrician can use to diagnose dwarfism.
Making a tentative prenatal diagnosis while the baby is still in the womb can be done with an ultrasound. 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 most common complications associated with disproportionate dwarfism are:
- bowed legs
- progressive hunching of the back
- narrowed channel in the lower spine, resulting in pressure on the spinal cord (spinal stenosis)
- spinal pressure at the base of the skull
- excess brain fluid (hydrocephalus)
- sleep apnea
- delays in motor skills development as a baby
- weight gain that can place more strain on the spine and joints
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.
Dwarfism, regardless of the cause, can’t be cured or “corrected.” However, there are certain therapies that may help reduce the risk of complications.
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.
Girls with Turner’s syndrome need estrogen therapy and other hormones to help trigger puberty and appropriate female development. Estrogen therapy may be necessary until a woman reaches the age of menopause.
For others with dwarfism, surgical treatments may be necessary and helpful to living a longer, healthier life.
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.
Living with dwarfism
Dealing with prejudices and ignorance in society can be difficult. There may also be everyday challenges associated with living with dwarfism.
Organizations such as LPA provide resources to help with the emotional and logistical challenges in life. 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 percent chance their child will inherit the unaffected gene and grow to at least an average height.
There is a 50 percent chance of the child inheriting one of each type of gene, but a 25 percent 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 have 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.