Skeletal Dysplasia in Children

What is skeletal dysplasia? 

Skeletal dysplasia is a group of genetic conditions that affect the growth of bones, joints and cartilage. Mild cases can cause small stature and shorter legs and arms. More severe cases of skeletal dysplasia can also affect a child’s vision, hearing, breathing and mobility. In rare cases, some affect intelligence or learning.

There are more than 700 known types of skeletal dysplasia, and most are extremely rare. The most common type, achondroplasia, occurs in about 1 in 25,000 people. Some of the more common types of skeletal dysplasia include:

• Achondroplasia: Bone growth slows, especially in the long bones of the arms and legs. Children with achondroplasia have dwarfism, identified by short arms and legs, a larger head and a more pronounced S-shape in their spine.
• Hypochondroplasia: Similar to a mild form of achondroplasia with less pronounced short stature and short limbs.
• Type 2 collagen disorders: A group of several different conditions with a wide spectrum of symptoms from children who only have vision problems to those with severe short stature, cleft palate, hearing loss and breathing concerns.
• Osteogenesis imperfecta: Also known as brittle bone syndrome, children with this condition have fragile bones that break easily.
• Pseudoachondroplasia (PSACH): Bone growth starts to slow around 1 to 2 years old and leads to dwarfism and other differences in bone growth, often causing a waddling walk and bowlegs or knock knees
• Multiple epiphyseal dysplasia (MED): A milder form of skeletal dysplasia that mainly affects the legs, hips and knees and sometimes causes short stature. Children may have joint pain and early-onset arthritis.
• Campomelic dysplasia: A more severe type of skeletal dysplasia causing bowing (bending) of the leg and arm bones, hip dislocations and club feet.
• Metatropic dysplasia: Children have short limbs as babies and usually develop stiff joints, a short torso and spinal curvature as they grow.
• Thanatophoric dysplasia: A severe skeletal condition with very short limbs and stature, bowed legs, a small chest and spine problems.

What causes skeletal dysplasia? 

Genetic factors cause skeletal dysplasia. Sometimes conditions are passed on by parents to children, but in many cases, they’re caused by a new genetic change that isn’t inherited. Skeletal dysplasia is not caused by environmental factors or affected by anything a parent does while pregnant.

Who gets skeletal dysplasia?

Any family can have a child affected by skeletal dysplasia. Parents can pass genetic conditions down to children, but most are caused by new, random genetic changes in a child that parents have no control over. Skeletal dysplasia affects about 1 in 5,000 children, and conditions can vary widely in severity.

What are the signs and symptoms of skeletal dysplasia? 

Signs of skeletal dysplasia can sometimes be seen prenatally (before birth) or at birth, but they can also appear later as a child grows and develops. Short stature is the most common symptom of skeletal dysplasia. Other signs can appear in many areas of the body including the arms, legs, spine and torso.

Skeletal dysplasia symptoms vary by type and may include:

• Large head compared to the rest of the body
• Legs that bow inward or outward (knock knees or bow legs)
• Stiff joints that don’t move easily in the feet, knees, ankles, wrists or fingers
• Joints that move too easily
• Short arms and legs compared to the rest of the child’s body
• Short torso compared to arms and legs
• Feet that curve inward
• Spinal curvature
• Short fingers or toes
• Small chest cavity that makes breathing hard
• Hearing loss
• Vision concerns like nearsightedness

How do we diagnose skeletal dysplasia? 

We can sometimes diagnose skeletal dysplasia during pregnancy via a prenatal ultrasound. Generally, the earlier we can detect it during an ultrasound, the more severe the diagnosis. Because the condition is genetic, our Colorado Fetal Care Center offers genetic testing, which may detect skeletal dysplasia even earlier than an ultrasound. This helps us better advise parents and helps the care team prepare for the baby's delivery and immediate care.

If specialists don't identify skeletal dysplasia during pregnancy or immediately after birth, you or your child’s pediatrician may see symptoms as your child grows. Our doctors may request imaging or other testing and often work with specialists across our hospital to ensure your child’s care team is prepared for your child’s specific needs. 

What tests do we use to diagnose skeletal dysplasia? 

• X-ray: A quick and painless test that produces pictures of the inside of your child’s body
• Computed tomography (CT) scan: X-ray beams and detectors create a series of photos to produce a more complete view inside your child’s body
• Magnetic resonance imaging (MRI): Uses magnetic field and radio waves to view different parts of your child’s body
• Genetic testing and screening: Provides you with health information either before pregnancy, during pregnancy or after birth to learn how genetic conditions may affect your child and family or if your baby may inherit a condition like skeletal dysplasia
• Urine tests: Sometimes a simple urine test to detect certain substances can help diagnose skeletal dysplasia

How do we treat skeletal dysplasia? 

There is no cure for skeletal dysplasia, but we’ll create an individual treatment plan based on your child’s specific diagnosis and needs to help them be as active, comfortable and engaged as possible. Based on the type of skeletal dysplasia your child has, its severity and their needs, treatment may include:

• Reducing pain so your child is as comfortable as possible
• Using medicine to change or speed up bone growth
• Surgery to correct bone growth
• Observing your child’s growth to get a better idea about the best treatment
• Looking for vision, hearing and dental concerns

Why choose us for treatment of skeletal dysplasia? 

At Children’s Colorado, we set the standard for quality pediatric orthopedic care. We are one of only a few children’s hospitals that provide care from before birth into adulthood from nationally recognized experts in the field of skeletal dysplasia care and research. Children with skeletal dysplasia receive all the care they need in our multidisciplinary care clinic, so you don’t have to travel to different hospitals to see different specialists. Our team provides a medical home for these rare conditions to add to the care provided by your pediatrician.

As children learn and grow, our care is tailored to help your child where they are and get them to where they want to go. We care for kids, and only kids, because our experts know how different they are from adults, especially for orthopedic care.

Our team’s advanced training and access to cutting edge pediatric research, imaging and technology means that we can diagnose and treat many types of skeletal dysplasia. As leaders in research, we offer the most innovative treatments to ensure children receive the best possible outcomes and quality of life. Every child, condition and treatment are different, and we work as a team to provide the best care possible.

Learn more about research at the Orthopedic Institute

Helpful resources

• Little People of America
• Understanding Dwarfism
• Dwarf Athletic Association of America
• Courageous Parents Network
• Parent-to-Parent
• Family Voices
• Make-A-Wish Foundation