What Is Dwarfism?
Here are some facts that people may not realize about dwarfism.
- is characterized by short stature. This means an adult height of 4 feet 10 inches or under, according to the advocacy group Little People of America (LPA). For children, this means being below the height growth curve for their age, which would be less than the 2nd percentile.
- can and most often does happen in families where both parents are of average height
- can be caused by any one of more than 400 conditions. Most of these are genetic and classified as skeletal dysplasias (conditions of unusual and bone growth).
The most common type of dwarfism is achondroplasia (ay-kon-dreh-PLAY-zyuh).
- an intellectual disability. Most people with dwarfism have normal intelligence.
- a disease that requires a "cure." Most little people live long, fulfilling lives.
- a reason to assume someone is incapable. Little people go to school, work, drive cars, marry, and raise children, just like their average-size peers.
What Causes Dwarfism?
Most types of dwarfism are caused by a genetic change (mutation) in the egg or sperm cells before conception. Others happen because of genetic changes inherited from one or both parents.
Depending on the type of dwarfism, two average-size parents can have a child with short stature. It's also possible for parents who are little people to have an average-size child.
What makes a gene mutate is not yet well understood. The change seems to be random and unpreventable, and can happen in any pregnancy. If parents have some form of dwarfism themselves, the chances are higher that their children also will be little people. A genetic counselor can help determine the likelihood of passing on the condition in these cases.
What Are the Types of Dwarfism?
Does everyone with dwarfism look alike? Not at all. Everyone with dwarfism is short, but different types of dwarfism have different causes and different physical traits.
Most types of dwarfism are skeletal dysplasias (diss-PLAY-zhee-uhs). There are more than 400 different types of these unusual cartilage and bone growth conditions.
In general, dwarfism caused by skeletal dysplasias results in disproportionate short stature. This means that the limbs and the trunk are not of the same proportion as those of typically statured people.
The two types of this disproportion are short-trunk and short-limb:
- People with short-trunk dwarfism have a shortened trunk with more average-sized limbs.
- People with short-limb dwarfism have a more average-sized trunk with shortened arms and legs.
By far the most common skeletal dysplasia is achondroplasia. This short-limb dwarfism happens in about 1 of every 25,000 babies born of all races and ethnic groups. People with achondroplasia have a relatively long trunk and shortened upper parts of their arms and legs. This is called rhizomelic shortening. They also may have:
- a larger head with a prominent forehead
- a flattened bridge of the nose
- shortened hands and fingers
- a sway of the lower back
- bowed legs
The average adult height for someone with achondroplasia is a little over 4 feet.
Diastrophic dysplasia is another short-limb dwarfism. It happens in about 1 in 100,000 births. People who have this type tend to have shortened forearms and calves (called mesomelic shortening). They might also have:
- a cleft palate
- ears with a cauliflower-like appearance
- differently positioned thumbs (also called hitchhiker thumbs)
- inward or downward pointing feet
- spine curves that get worse over time
Most people with diastrophic dysplasia have joint problems that limit movement. Along with the curved spine, this can make it hard to walk distances, especially when they get older. Some people may need to use crutches, a scooter, or a wheelchair to get around.
Spondyloepiphyseal dysplasias (SED) are short-trunk skeletal dysplasias that involve the spine and the end of the bones that make up the joints (epiphyses). Along with achondroplasia and diastrophic dysplasia, they're one of the more common types of dwarfism. In one type of SED, the short trunk may not be noticed until the child is school age. Other types are seen at birth. Kids with an SED also might:
- be born with clubfeet and/or cleft palate
- have vision and/or hearing problems
- have instability of the spine and/or curvatures that can get worse over time
- develop reduced joint mobility and arthritis early in life
How Is Dwarfism Diagnosed?
Doctors sometimes suspect achondroplasia before birth if a prenatal ultrasound late in a pregnancy shows that a baby's arms and legs are shorter than average and the head is larger. But most moms do not have these late ultrasounds, so many children with achondroplasia are not diagnosed until after birth.
Doctors can diagnose some types of dwarfism earlier in pregnancy. Others aren't diagnosed until the first few months or years of life, when a child's growth slows.
If a child may have dwarfism caused by a skeletal dysplasia, X-rays after birth can see if and how the bones are shaped differently. Also, doctor sometimes use genetic testing before or after birth to confirm the diagnosis.
Possible Complications and Treatments
People with dwarfism can lead healthy, active lives. The conditions that cause dwarfism have their own possible complications, which can change over time. But doctors can treat many of these.
Some medical issues are treated with surgery, usually on the back, neck, leg, foot, or middle ear. So, little people usually have more surgeries than the average-size person, especially as children. These are done with anesthesia, which can be more of a risk for little people because of their smaller body size and airways.
Because of their shorter stature and differences in bone growth, children with dwarfism usually learn to roll over, sit up, and walk at older ages than average-size kids. But they do figure out how to do it in their own time and in their own way.
A few extra pounds on a little person can be more of a problem than a few extra pounds on an average-size person. Extra weight puts harmful stress on the back and joints. Little people might have limits on the types of exercises and activities that they can do. But it's important for them to find safe physical activities that they enjoy to help stay fit.
Most of the complications that happen in people with dwarfism are physical, not intellectual. In fact, little people often find clever ways to do things in the average-size world. They also interact with people unfamiliar with dwarfism who make assumptions about it. While that can be tough and awkward at times, it's also an opportunity to enlighten people who don't know much about dwarfism.
How Can Parents Help?
Types of dwarfism, and their severity and complications, vary from person to person. In general, a child's life span is not affected by being little. The Americans with Disabilities Act protects the rights of people with dwarfism, but many members of the short-statured community don't feel that they have a disability.
You can help your child with dwarfism lead the best life possible by building his or her sense of independence and self-esteem right from the start.
Here are some general tips to keep in mind:
- Treat your child according to his or her age and developmental level, not size. A 2-year-old should not still use a bottle, for example, even if she's the size of a 1-year-old. And, if you expect a 6-year-old to clean up his room, don't make an exception because your child is small.
- Adapt to your child's limitations. Simple things like a light switch extender or a step-stool can give a short-statured child a sense of independence around the house.
- Treat your child's condition as a difference, not a problem. Your attitude and expectations can greatly influence your child's self-esteem.
- Ask how your child wants to refer to their dwarfism. Some people prefer "little people" or "person of short stature."
- React to people's reactions without anger. Address questions or comments as directly as possible, then point out something special about your child. Your child will see that you notice the qualities that make him unique. You also show that the dwarfism doesn't make you angry. This helps prepare your child for dealing with these situations when you're not there.
- If your child is teased at school, don't overlook it. Talk to teachers and administrators to make sure your child is getting support.
- Help your child learn about dwarfism and the health care needed over time and as your child gets older and more independent.
- Encourage your child to find a hobby or activity to enjoy. Check with your doctor about any sports to avoid. If sports aren't your child's thing, maybe music, art, computers, writing, or photography will be.
- Stay active together as a family. If needed, choose or adapt the activity so your child can join.
- Refer family and friends to websites that can help them learn about dwarfism, such as:
- Find support from groups like Little People of America. Getting to know other people with dwarfism — both as peers and mentors — can show kids how much they can achieve.
- Dwarfism Factsheet (for Schools)
- Dwarfism: Emily's Story (Video)
- Newborn Screening Tests
- What Is a Growth Disorder?
- Prenatal Tests: FAQs
- Occupational Therapy
- Physical Therapy
- Genetic Testing