Dwarfism (Skeletal Dysplasia) and Other Causes of Short Stature

Overview

What is dwarfism?

Dwarfism (a form of skeletal dysplasia) is an umbrella medical term that includes hundreds of conditions that affect the growth of bone and/or cartilage, resulting in short stature. People with this condition are usually less than 4 feet 10 inches tall as an adult.

Some people with these conditions prefer identifying themselves as “little people,” but the term “midgets” should not be used.

Dwarfism has many different forms. These conditions can affect different parts of the musculoskeletal system including the growth of the arms, legs, abdomen and/or head.

What are common types of dwarfism (skeletal dysplasia)?

Hundreds of types of dwarfism (skeletal dysplasia) affect bone growth. Some of the most common types include:

  • Achondroplastic dwarfism: The most common form of dwarfism is characterized by short limbs and a prominent forehead.
  • Hypochondroplasia dwarfism: A mild type of short-limbed dwarfism with characteristics not noticeable during infancy.
  • Pituitary dwarfism: Dwarfism caused by a growth hormone deficiency.
  • Primordial dwarfism: A form of dwarfism where a small body size occurs during all stages of life, even before birth.
  • Thanatophoric Dysplasia: A less common very severe form of dwarfism that causes very short limbs along with a narrow chest. It usually causes infants to die shortly after birth due to breathing difficulties.

What does short stature mean?

“Short stature” is a term that refers to a person who is shorter than expected for people the same age. In children, this can mean that their height is below typical growth curves or less than expected based on their parents’ heights.

Several factors determine a person’s standing height (or length in babies) including how tall their parents are, their weight and hormone levels. Many genetic conditions can cause people to have short stature.

Who does dwarfism affect?

Dwarfism (skeletal dysplasia) can affect anyone. Many types of dwarfism are genetic, which means you can inherit the condition from your parents and other forms occur randomly through DNA changes. Most often, but not always, dwarfism affects children of parents with average height.

How common is dwarfism?

Dwarfism (skeletal dysplasia) is a rare condition. The most common type of dwarfism is achondroplasia, which affects 1 in 15,000 to 40,000 people.

How does dwarfism affect my body?

Dwarfism (skeletal dysplasia) affects bone growth in your body. The most common bones that dwarfism affects are the long bones in the arms and legs, but it can affect other bones including the bones in your arms and legs as well as your abdomen and head. Symptoms of dwarfism can affect other parts of your body and lead to long-term health problems, like weak muscle tone or frequent infections.

Symptoms and Causes

What are the symptoms of dwarfism?

The most common symptom of dwarfism (a form of skeletal dysplasia) is short stature. A person diagnosed with any type of dwarfism will almost always have a height below 4 feet 10 inches as an adult. Short stature is more noticeable during puberty and adulthood rather than during childhood.

Most causes of being short are proportionate, meaning that everything is small and not just certain parts of your body. Some forms of dwarfism refer to short stature as disproportionate, which means that a person has an average-sized torso and short arms and legs.

Symptoms of dwarfism can include:

  • Bowed legs.
  • Flat nasal bridge (bony area at the top of the nose).
  • Large head.
  • Prominent forehead.
  • Short arms and legs.
  • Short fingers and toes.
  • Wide hands and feet.

Symptoms of dwarfism can sometimes lead to additional health concerns for people diagnosed with the condition due to their abnormal bone growth including:

What causes dwarfism?

Several potential causes lead to a dwarfism (skeletal dysplasia) diagnosis. A change to a person’s DNA causes most cases of dwarfism, while several types have an unknown cause.

Causes of dwarfism include:

  • Familial: If parents and other family members are short, it can be normal for their child to be short.
  • Genetic mutation: Changes to a person’s DNA.
  • Growth hormone deficiency: The brain doesn’t make enough of the hormone that causes bones to grow.
  • Late bloomer (constitutional delay): Some children are short earlier in childhood because they are programmed to grow later than their peers. There is sometimes a family history of a similar pattern of growth.
  • Malnutrition: Not having adequate nutrition can affect a child’s ability to grow.
  • Small for gestational age: Most babies that are born small will catch up with their growth within the first two to three years of life, but 10% do not.

Is dwarfism genetic?

Yes, some types of dwarfism (caused by a skeletal dysplasia) are genetic and are the result of a change in a person’s DNA. In most cases, the genetic mutation happens randomly and is not passed from a short-statured parent to a child. This means that most parents who have children diagnosed with dwarfism are of average height.

The rate that a child will inherit the condition increases if one or both parents have a dwarfism diagnosis and can be different depending on which form of dwarfism a person has. For example, a parent with achondroplasia has a 50% chance of passing the condition onto their child. If both parents have achondroplasia, there is a 25% chance their child will be born with a dangerous form of dwarfism called homozygous achondroplasia, which leads to stillbirth or death shortly after birth and a 50% chance for typical achondroplasia.

If you plan on becoming pregnant and want to understand your risk of having a child with an inherited condition like achondroplasia or dwarfism, contact your healthcare provider about genetic testing.

Diagnosis and Tests

How is dwarfism diagnosed?

Your healthcare provider can diagnose dwarfism (skeletal dysplasia) before birth, in some cases. During pregnancy, your provider will use prenatal screening tests to identify any growth abnormalities in your child.

After your child is born, your provider will keep track of your child’s growth during annual wellness visits. If your baby did not receive an early diagnosis of dwarfism (skeletal dysplasia) at birth, a diagnosis could come later if your child misses growth milestones, which are a sign of the condition. Additional tests, like an X-ray and blood tests, can help your provider identify why your child isn’t growing at a normal rate, which will lead to their diagnosis.

Management and Treatment

How is dwarfism treated?

Treatment for dwarfism (skeletal dysplasia) is unique for each person based on their specific diagnosis and addresses symptoms of the condition since there is no cure.

Surgical treatment to address symptoms could include surgery to:

  • Correct bones growing in an abnormal direction or the shape of bones.
  • Remove excess fluid from around the brain (hydrocephalus).
  • Reduce brain stem compression, which is pressure on the part of the brain that connects to the spinal cord.
  • Improve breathing by removing tonsils and/or adenoids.
  • Add tubes in the ears to prevent ear infections.

Other types of treatment to address symptoms of dwarfism (skeletal dysplasia) that don’t involve surgery include:

  • Using a CPAP machine for sleep apnea.
  • Using hearing aids to improve hearing.
  • Encouraging healthy eating habits and exercise to prevent excess weight gain or obesity.
  • Taking growth hormones (hormone therapy) to treat a growth hormone deficiency.

Treatment for dwarfism is lifelong and helps improve a person’s quality of life.

Prevention

How can I reduce my risk of having a child with dwarfism?

Since some types of dwarfism (skeletal dysplasia) are genetic, there is no way to prevent the condition unless a technology like pre-implantation genetic testing were to be used. To better understand your risk of having a child with a genetic condition like dwarfism, contact your healthcare provider about genetic testing.

Nutrition plays a vital role in your child’s growth. If you are pregnant, make sure you eat a healthy diet. When your child is born, they should also eat a variety of healthy, age-appropriate foods, like protein, fruits, grains and vegetables, which will give them all the nutrients they need to grow.

Outlook / Prognosis

What can I expect if I have a child diagnosed with dwarfism?

Although there is no cure for dwarfism (skeletal dysplasia), many people of short stature have a normal life span and good health with treatment to address their symptoms. There are potential symptoms of the condition that could take a toll on your child and your family, especially if their abnormal bone growth requires multiple surgeries. Your healthcare provider will work closely with you and your child to make sure they receive the treatment they need to live a full and healthy life.

What is the life expectancy for someone with dwarfism?

For many forms of dwarfism, people diagnosed have a normal life expectancy with treatment to manage their symptoms. For other forms, unfortunately, the lifespan is shortened.

Living With

How do I take care of my child with dwarfism (skeletal dysplasia)?

Once your child’s medical needs are met, you can support them by creating an environment that welcomes them and makes them feel included by:

  • Removing physical challenges in your home to promote independence (using a step stool, lowering light switches).
  • Providing educational and/or emotional support to prevent bullying in school.
  • Engaging with organizations that support children with similar diagnoses (Little People of America, Inc.).

Parents should balance the need to treat their children in a way that is appropriate for their age, not their height.

What questions should I ask my doctor?

  • Does my child need surgery to treat their symptoms?
  • How can I help my child prevent ear infections?
  • Are there side effects to the treatment you recommend?
  • How often does my child need to take growth hormones?

A note from Cleveland Clinic

Although your child diagnosed with dwarfism (skeletal dysplasia) might need surgery or long-term treatment to manage their symptoms, it doesn’t necessarily mean they can’t live a full and meaningful life. As their caregiver, remember to treat your child according to their age, not their height. This will improve your child’s self-esteem and help them feel included and loved.

Last reviewed by a Cleveland Clinic medical professional on 07/26/2022.

References

  • Little People of America. Frequently Asked Questions. (http://www.lpaonline.org/faq-#Disability) Accessed 7/27/2022.
  • March of Dimes. Achondroplasia. (https://www.marchofdimes.org/baby/achondroplasia.aspx) Accessed 7/27/2022.
  • National Health Services. Restricted Growth (Dwarfism). (https://www.nhs.uk/conditions/restricted-growth/) Accessed 7/27/2022.
  • National Human Genome Research Institute. Learning About Achondroplasia. (https://www.genome.gov/19517823/learning-about-achondroplasia/) Accessed 7/27/2022.
  • National Library of Medicine. Dwarfism. (https://medlineplus.gov/dwarfism.html#summary) Accessed 7/27/2022.
  • National Organization for Rare Disorders. Growth Hormone Deficiency. (https://rarediseases.org/rare-diseases/growth-hormone-deficiency) Accessed 7/27/2022.
  • U.S. Department of Health & Human Services. Achondroplasia. (https://rarediseases.info.nih.gov/diseases/8173/achondroplasia) Accessed 7/27/2022.

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