Dwarfism

What is dwarfism?

Dwarfism is a form of skeletal dysplasia — a range of genetic conditions that affect bone, joint and cartilage growth resulting in shorter-than-average height. Adults with dwarfism are usually under 4 feet 10 inches tall. Most people with dwarfism, especially the common types like achondroplasia, have a typical life expectancy.

What causes dwarfism?

More than 300 medical conditions cause dwarfism. Most often, dwarfism is the result of a genetic change that happens randomly at conception. Parents of a child with dwarfism are usually average height. In some cases, a child may inherit the gene mutation that causes dwarfism from one or both parents.

Common conditions that cause dwarfism include:

• Genetic bone disorders: Achondroplasia is the most common cause of dwarfism (called achondroplastic dwarfism). This genetic bone disorder limits bone growth, especially in the arms and legs. Other bone disorders that can cause dwarfism include hypochondroplasia, type 2 collagen disorders, osteogenesis imperfecta (brittle bone disease) and other skeletal dysplasia conditions.
• Hormone deficiencies: A low level of growth hormone is the most common hormonal cause of dwarfism (called pituitary dwarfism). It happens when the pituitary gland does not produce enough of the hormone that helps bones grow. Low levels of other hormones, like hypothyroidism, can also cause dwarfism.
• Other genetic conditions: Conditions like Down syndrome and Turner syndrome can result in dwarfism.
• Systemic disorders: A wide range of other conditions that affect a child’s entire body, such as poor nutrition, problems with metabolism,  diabetes, cystic fibrosis or chronic kidney disease, can cause dwarfism.

What is the difference between dwarfism and short stature?

Dwarfism is the medical term for a group of conditions that cause short height, typically 4 feet 10 inches or shorter as an adult. People with dwarfism usually have disproportionate growth, meaning their arms, legs or torso grow unevenly compared with the rest of the body.

Short stature is a general term for a height that is below average for a person’s age and sex. Many people with short stature have no underlying medical conditions. Common causes include genetics (short parents), growth delays and poor nutrition.

What are the signs and symptoms of dwarfism?

The main symptom of dwarfism is short stature, with adult height usually less than 4 feet 10 inches. Short stature may be either:

• Proportionate, with arms, legs and torso that are all smaller than normal
• Disproportionate, such as shorter arms and legs with an average-sized torso or a shorter torso with average-length arms and legs

Depending on the cause of dwarfism, other common signs and symptoms may include:

• Curved spine
• Delayed development, like learning to walk later than usual
• Flattened nose bridge
• Frequent ear infections
• Joint problems, such as looseness, stiffness or pain
• Knock knees or bowlegs
• Large head with a prominent forehead
• Narrowed vertebrae (spine bones)
• Short fingers and toes
• Small lungs causing breathing problems
• Slow or stopped breathing (apnea) for short periods

How do we diagnose dwarfism?

Dwarfism diagnosis in babies uses a combination of evaluations, including:

• A physical exam
• Blood tests to check hormone levels and metabolism
• Genetic testing
• Medical history
• X-rays to check bone growth, especially in the arms and legs

In some cases, your doctor may also recommend additional tests, like an MRI to check your child’s spine, a sleep study to check for sleep apnea or a urine test to check kidney function.

Occasionally, a doctor sees signs of dwarfism during a fetal ultrasound. Amniocentesis (a test that uses a small sample of amniotic fluid) can confirm the diagnosis.

How do we treat dwarfism?

Based on the cause of dwarfism, we develop a personalized plan to monitor and treat your child’s specific symptoms. This may include:

• Head and body measurements until age 2 to track growth and monitor for hydrocephalus (fluid buildup in the brain)
• Medicines to promote growth
• Orthopedic care to fix spine problems and bowed legs
• Occupational therapy to help with daily activities
• Over-the-counter medicines to reduce joint pain
• Physical therapy to help with developmental delays and reduce joint stiffness
• Sleep studies to check for sleep apnea
• Speech-language therapy to improve speech, language, thinking and socializing
• Treating frequent ear infections to prevent hearing loss
• Using adaptive aids, like foot and seat supports for school desks or extended door handles

Why choose us for treatment of dwarfism?

Dwarfism affects many areas of life. As a Rare Disease Center of Excellence, we have specialists with the highest level of expertise in treating rare forms of dwarfism. Our care teams include all the experts your child needs based on their specific situation, such as orthopedists, endocrinologists, genetic counselors and rehabilitation specialists.

Our Skeletal Dysplasia Program is among only a few complete children’s programs that provide care from before birth into adulthood. Our eXtraOrdinary Kids Turner Syndrome Clinic is nationally recognized for care of children, adolescents and young adults with Turner syndrome. For dwarfism caused by hormone deficiencies, experts in our Department of Pediatric Endocrinology, ranked third in the nation by U.S. News & World Report, offer advanced care. No matter the nature of your child’s dwarfism, we have a team of experts to help.

Your child also has access to emerging treatments such as growth hormone treatments that are not always available at other children’s centers through our dwarfism research programs.

Helpful resources

• Human Growth Foundation
• Little People of America
• Understanding Dwarfism