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Hospital Sant Joan de Deu

Hospital Sant Joan de Deu Barcelona
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Dwarfism

What Is Dwarfism?

Here are some facts that people may not realize about dwarfism.

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 (prnounced: ay-kon-dreh-PLAY-zyuh).

Dwarfism isn't:

  • 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 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 (pronounced: 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. 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. Someone with an SED also might:

  • have had clubfeet and/or a cleft palate at birth
  • 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 can diagnose some cases of achondroplasia before birth by doing an ultrasound in the later stages of pregnancy. The ultrasound can show if a baby's arms and legs are shorter than average and if the baby's head is larger.

Different types of dwarfism can be diagnosed even earlier in pregnancy, but other types aren't found until a baby is born. If it's thought a child may have dwarfism, the doctor can use X-rays after birth to see if the bones are growing at an unusul rate, or if they are shaped differently.

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.

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.

What Else Should I Know?

Types of dwarfism, and their severity and complications, vary from person to person. In general, a person'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.

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.

Date reviewed: September 2019