What Is Achondroplasia Dwarfism?

Written by Nichole Owens
Medically Reviewed by Brunilda Nazario, MD on November 03, 2025
11 min read

Achondroplasia dwarfism is a bone growth condition you have from birth. Achondroplasia means “no cartilage growth.” Cartilage is the strong, flexible connective tissue that protects your joints and bones. When you have this condition, you don’t grow to a typical height.  

Achondroplasia vs. dwarfism (skeletal dysplasia)

Skeletal dysplasia is the broad term for conditions that cause problems with the way bones and cartilage grow. Achondroplasia dwarfism is the most common type of skeletal dysplasia.  

Achondroplasia primarily affects bone growth in the arms, legs, vertebral column, pelvis, and skull.

Achondroplasia happens when there’s a change (mutation) in the genes that affect the fibroblast growth factor receptor (FGFR3). This protein plays a key role in bone growth within the growth plate and cells found in cartilage. In achondroplasia, this protein doesn’t work like it should. As a result, bone growth stalls, bone cartilage is impaired, and bones become abnormally shaped.

Is achondroplasia hereditary?

It’s possible to inherit a gene for achondroplasia from one or both of your parents. The trait is autosomal dominant, which means there’s a 50% chance of getting it from a parent if one of your parents has the mutated gene. But most cases aren’t inherited. 

Anyone can be born with achondroplasia. Most children who are born with it — more than 80% — have a spontaneous genetic mutation that happens just before birth, and neither parent has the condition.

It’s also rare for people of normal height who have a child with achondroplasia to have another child with the condition.

Achondroplasia risk factors

About 99% of cases of achondroplasia result from the exact same change in the DNA of the FGFR3 gene.

Achondroplasia happens equally in people assigned male at birth and people assigned female at birth. You may be at slightly higher risk if your father is 35 years old or older when you’re born. 

Around 1 in every 10,000 to 30,000 live births have achondroplasia.

If you’re an adult living with achondroplasia dwarfism, it’s important to take care of your physical, mental, and emotional health. Stay on top of regular medical checkups, and get treatment for physical pain or conditions like sleep apnea.

Make small modifications, such as installing light switch extenders or lever-style door handles, to make your home safer, more comfortable, and functional. Consider using adaptive devices, such as mobility aids, handrails, and step stools to help you move around with ease.

The Little People of America website has a list of mental health and support resources as well as a list of local and regional chapters and events where you can connect with others living with achondroplasia dwarfism. If you’re dealing with depression or anxiety, consider professional counseling.

Not everyone with the condition will have the exact same symptoms and not all symptoms will be obvious at birth. Symptoms that are common include:

  • Shortened thigh bone and upper arm bone length
  • Short hands and feet
  • Short fingers
  • Larger head size
  • Prominent forehead that curves outward above the eyebrows (frontal bossing)
  • Flattened bridge of the nose
  • Knees splay out (bowlegs) or knees that turn in (knock-knees)
  • Limited elbow mobility and loose joints everywhere else
  • Large separation between the middle finger and ring finger (trident hand)
  • Curvature of the spine

What’s the first sign of achondroplasia?

Your doctor may suspect achondroplasia during pregnancy if an ultrasound shows your baby’s arms and legs are shorter than average or if their head is large. At birth, babies with achondroplasia may have a bigger than usual head with a broad forehead and flatter face. Their chests are slightly narrow and arms and legs are shorter than normal.

What are the long-term symptoms of achondroplasia?

As children with achondroplasia get older, it can cause:

  • Delayed growth or no growth spurt 
  • Slow motor development milestones
  • Sleep apnea
  • Frequent ear infections
  • Obesity
  • High blood pressure 
  • Crowded or crooked teeth
  • Narrowing of the vertebral spaces that can lead to spinal compression

A small percentage of babies born with achondroplasia have fluid buildup in the brain (hydrocephalus). 

Most adults with achondroplasia grow to be around 4 feet 6 inches or less.

Doctors can diagnose achondroplasia during the third trimester of pregnancy using ultrasound imaging to measure bones. DNA testing can confirm the diagnosis. Typically doctors do this if one or both parents have achondroplasia themselves. 

Testing for achondroplasia

To test DNA before birth, your doctor might use amniocentesis (using a needle to remove fluid from the amniotic sac for testing) or chorionic villus sampling (taking tissue from the placenta for testing).

Most cases are diagnosed after birth. Typically, when obvious signs are seen a physical exam is all that’s needed for a doctor to diagnose your child. But because there are treatments now for achondroplasia, some parents and doctors prefer a DNA confirmation so they can use those treatments.

DNA testing looks for a mutation in the FGFR3 gene.

To diagnose your born child with achondroplasia, a doctor may order several tests, including:

  • X-rays
  • MRI or CT scan to identify spinal stenosis or narrowing of the spinal column

What to expect after a diagnosis

If your baby is diagnosed with achondroplasia, their doctor will monitor them closely for their first two years of life. Every few years, their doctor may check them for other complications. 

Children with achondroplasia tend to crawl and walk later than children without this condition. They will need X-rays periodically to look at their spine for compression issues.

When you get a diagnosis of achondroplasia, you’ll likely have many questions for your doctor. You might ask:

Other typical questions might include:

  • Does my child need diagnostic tests?
  • What specialists will we need to see?
  • Are there screenings for symptoms or complications that my child will need?
  • Can you suggest educational materials and local support services for dwarfism?

Your child can live a full and healthy life with achondroplasia. The condition itself doesn’t need treatment, but doctors are working on medicines that promote bone growth in children with achondroplasia, as well as gene therapy. 

Most of achondroplasia management involves monitoring symptoms and treating any that interfere with health or daily activities.

Managing achondroplasia symptoms

Vosoritide (Voxzogo) is a medication given by injection. It’s approved for children of any age to increase linear growth and open growth plates. This medication hasn’t been shown to change the orthopedic or medical complications of this achondroplasia. Other medications used to boost linear growth are in development.

Some doctors may prescribe growth hormones, but this doesn’t typically add significant height for people with achondroplasia. 

If sleep apnea is a problem, you can use a continuous positive airway pressure (CPAP) nasal mask that helps get more oxygen to the body while you sleep.

Weight management is part of achondroplasia care. Obesity is common, and maintaining a healthy weight can also help with sleep apnea. 

Some kids may need tubes in their ears to help with frequent ear infections and prevent hearing loss. 

Sometimes people with achondroplasia have a curved spine and may need a brace or even surgery to help straighten it.

Procedures for achondroplasia

You may need surgical help with some of the complications of achondroplasia. Some surgeries you might need include:

  • Surgery to remove your adenoids and tonsils to help with breathing
  • Surgery to lengthen legs or correct bowing of the legs
  • Procedure to put a shunt in the brain to decrease fluid pressure in case of hydrocephalus
  • Surgery to relieve spinal stenosis or the narrowing of the spinal canal 

As you get older, you have a higher risk of complications from achondroplasia, such as chronic pain, issues with mobility, and spine or cardiovascular conditions. You may have some or all of the following:

  • Spinal stenosis, a narrowing of the spinal canal that gets worse over time
  • Kyphosis and lordosis, curving of the spine that can cause chronic pain and neurological problems
  • Osteoarthritis, caused by years of uneven pressure and weight on knee and ankle joints
  • Heart disease
  • Sleep apnea

Planning for how your child’s condition may change

From ages 3 to 5, your child may start to have complications affecting bones or muscles, as well as dental issues such as tooth overcrowding. Ear infections or fluid buildup may happen as well.

During middle childhood (ages 6 to 12), you may begin to notice more changes in your child’s body proportions. Their arms and legs may be shorter compared to their torso. Their legs may be more bowed, and they may show signs of narrowing of the spinal canal (spinal stenosis).

During the teen years (13 to 17), your child won’t have a growth spurt like their peers. They’ll be noticeably shorter than their peers, and most of their growth will be in their torso. They may also gain more weight than their peers. Your child may struggle with body image and self-esteem issues during this phase. 

Almost all people with achondroplasia have a normal life span and normal intelligence. While some complications can happen, and certain symptoms may need management, you can live a full life with achondroplasia. 

Certain brain and spine issues can happen as children grow faster than their bones, especially the bones at the base of the skull and spine. If the spinal cord and brain stem are compressed, complications can happen. These include:

Cervicomedullary myelopathy. The small hole at the base of the skull where the spinal cord extends from the brain down along the spine is called the foramen magnum. When compression happens here, it “kinks” the brain stem, causing symptoms such as numbness, instability, muscle weakness, loss of bladder control, and trouble walking.

Compression of the brain stem can cause death if it’s not treated. It’s important to have follow-up visits  as your child grows. Call your doctor right away if you see symptoms including: 

  • Headache
  • Double vision
  • Difficulty swallowing
  • Slurred, slowed speech

Hydrocephalus. The fluid that surrounds your brain and spinal cord is meant to flow freely. When narrowing at the base of the skull blocks the flow, the fluid collects in spaces of the brain called ventricles. 

If your baby has this, you’ll notice their head getting larger in a short amount of time. Your child may also have headaches, be irritable, vomit, or be lethargic. A doctor can diagnose the problem with an MRI or CT scan.

Spinal cord myelopathy. Vertebrae that don’t grow enough can press on nerves coming in and out of the spinal cord. Depending on which nerve is compressed, your child may have numbness or tingling in one arm or leg. They may favor one side over the other, or complain of back pain. 

Sometimes, spinal cord myelopathy can cause bladder and bowel issues. 

In addition to your health care team, you may find connection and support through organizations focused on growth conditions. You can find information and support for people with achondroplasia and their families at these places:

The Human Growth Foundation has social media groups for people to stay current on all things related to growth and bone conditions. You can also find private member-based groups and discussion forums. 

Little People of America is a national nonprofit organization with over 7,500 members that provides support and information to people of short stature and their families. They offer information on employment, education, disability rights, adoption, medical issues, clothing, adaptive products, and the many stages of parenting a short-statured child from birth to adult. 

The MAGIC Foundation is a charitable nonprofit organization created to provide support services for the families of children afflicted with a wide variety of chronic or critical conditions, syndromes, and diseases that affect a child's growth.  

Understanding Dwarfism is an online resource “dedicated to changing the world’s perception of a group of people who throughout history have been misunderstood and stigmatized because of their profound short stature.” Their resources educate families and others with personal stories, facts about people of short stature, and advocacy materials.

If you’re the parent of a child who has achondroplasia, your concerns about your child’s physical health and emotional and social well-being may affect your own mental health. Studies show that parents of children and adolescents who have this condition experience worse mental health on average than parents whose children don’t have it. 

 Support is available. Ask your primary care doctor or child’s school counselors about what type of psychological and social support groups exist in your area. You can also find support groups specifically for achondroplasia through organizations such as Little People of America (LPA).

Caring for your child’s emotional and mental health

It can be hard for kids to look different from their peers. As your child grows, they may grapple with stares or even bullying. You can support their emotional growth and give them tools to thrive.

 

You may see several types of specialists when you have achondroplasia. In addition to your child’s pediatrician, who will give them routine care and monitor overall health, other specialists can help you manage some of the symptoms and complications.

These include:

Achondroplasia dwarfism is a bone growth condition you have from birth that prevents you from growing to a typical height. It targets bone growth in the arms and legs. Most adults who have it grow to about 4 feet 6 inches or less. Most people who have achondroplasia live a normal lifespan and have no intellectual disability. There is no cure, but treatments can prevent or manage complications from the condition.

Here are some commonly asked questions about achondroplasia.

How early can achondroplasia be detected?

If you’re pregnant, your doctor may be able to detect achondroplasia on an ultrasound, as your baby’s arms and legs will be shorter than average and their head will be large. They can also detect the condition through DNA tests that look for a change in the FGFR3 gene, which regulates bone growth. 

Is achondroplasia a disability?

Achondroplasia is a rare genetic condition that is also considered a disability. People with this condition and other forms of dwarfism are protected from discrimination under the Americans With Disabilities Act (ADA).

What’s the best way to hold a baby with achondroplasia?

Always support your baby’s neck and back, spreading your palm wide when holding them. Lay your baby flat against your hand to help keep their back and spine straight. This will help prevent them from developing a curve in the lower part of their back. 

Is achondroplasia painful?

It can be. If you develop spinal stenosis — a condition where your spinal canal narrows, causing pressure on the spinal cord and spinal nerves — you could have back pain. If your pain is severe, you may need surgery to make more room for the spinal cord and nerves.

Print
View privacy policy, copyright and trust info
View privacy policy, copyright and trust info