Spondyloepiphyseal Dysplasia Congenita

What is spondyloepiphyseal dysplasia congenita?

Spondyloepiphyseal (pronounced spon-di-lō-ep-i-fiz-ē-al) dysplasia congenita (SEDC) is a rare genetic disorder that causes abnormalities in your bones, joints and eyes. The abnormalities begin during fetal development and are noticeable at birth.

People with SEDC often have:

• Abnormally formed joints in their spine, hips and knees.
• Skeletal dysplasia, a problem with bone and cartilage that affects growth.
• Short stature (height), including a noticeably short trunk, neck and limbs.
• Vision and hearing problems.

It’s also called:

• SED congenita.
• SED, congenital type.
• SEDc.
• Spondyloepiphyseal dysplasia, congenital type.

How common is spondyloepiphyseal dysplasia congenita?

This condition is rare, occurring in approximately 1 in 100,000 live births. About 175 cases have been reported.

What’s the difference between spondyloepiphyseal dysplasia congenita and spondyloepiphyseal dysplasia tarda?

SEDC is similar to spondyloepiphyseal dysplasia tarda (SEDT). But signs of SEDT usually don’t appear until age 6 to 8. “Congenita” means “at birth,” and “tarda” means “late.”

Other differences between the two conditions include the following:

• SEDT occurs only in men, but SEDC happens in both sexes equally.
• SEDT doesn’t usually involve retinal detachment, which is a risk in people with SEDC.

What causes spondyloepiphyseal dysplasia congenita?

A mutation in the COL2A1 gene causes SEDC. This gene is involved in making type II collagen. Collagen is a protein that helps form connective tissue throughout your body. It gives your tissues form and strength.

Type II collagen is found in cartilage and vitreous. Cartilage is a strong but flexible connective tissue throughout the body, such as your joints and ears. Vitreous is a gel-like liquid that fills the eyeballs.

Most cases of SEDC involve a de novo (new) gene mutation in people with no family history of the disorder. A de novo mutation occurs when a sperm meets an egg. It affects only that child, not that child’s siblings.

But the COL2A1 gene mutation can also be inherited from a parent.

What are the symptoms of spondyloepiphyseal dysplasia congenita?

The signs and symptoms of SEDC vary widely from person to person. Physical signs may include:

• A noticeably short trunk, neck and limbs.
• Short stature (height), reaching 3 to 4 feet (0.91 to 1.2 meters) in adulthood.
• A broad, barrel-shaped chest, perhaps with the breastbone or ribs sticking out.
• Clubfoot (when the feet turn inward), although hands and feet have average size and shape.
• Curved spine, such as scoliosis (sideways curve), kyphosis (outward curve), lordosis (inward curve) or a combination of curvatures.
• Different facial features, like wide-set eyes, flattened cheekbones or a cleft palate.
• Flattened or unstable vertebrae (bones in your spine).
• Hip joints or knee joints that turn inward.

Symptoms that can result from these developmental issues include:

• Arthritis.
• Decreased mobility (movement).
• Hearing loss.
• Joint stiffness, pain and dislocations.
• Sciatica, pressure on a nerve in the lower back, buttocks and back of your legs.
• Trouble breathing (if the condition affects chest or rib development).
• Vision problems, particularly severe nearsightedness and retinal detachment.
• Waddling gait (walk) or trouble learning to walk.
• Weak muscle tone (hypotonia).

People with SEDC generally don’t have learning disabilities. But they may not meet physical developmental milestones like sitting or walking by a particular age.

How is spondyloepiphyseal dysplasia congenita diagnosed?

A healthcare provider can diagnose SEDC based on the presence of physical signs and results of the following tests:

• Genetic testing to identify the COL2A1 gene mutation.
• X-rays of the entire skeletal system.
• Other imaging tests, such as CT scans (computed tomography scans) and MRI (magnetic resonance imaging).

Is there a cure for spondyloepiphyseal dysplasia congenita?

There’s no cure for SEDC. Instead, treatment aims to:

• Ease your symptoms.
• Fix skeletal abnormalities, if possible.
• Prevent complications like injuries and vision loss.
• Improve your strength and mobility.

What treatments are available for SEDC?

Treatment varies widely, depending on your specific issues and how severe they are.

You should be monitored regularly to detect and treat any problems early. Your healthcare team might include:

• Genetic counselors.
• Ophthalmologists, who treat eye disorders.
• Orthopedic surgeons, who specialize in bone and joint surgery.
• Physical therapists, who help people improve strength, movement and gait.
• Rheumatologists, who treat bone, muscle and joint diseases like arthritis.

Interventions might include:

• Assistive devices to help with mobility (for example, leg braces).
• Glasses to correct vision problems.
• Medications to relieve joint pain.
• Physical therapy.
• Surgery to correct curvature of your spine.
• Surgery to correct other joint problems, including joint replacement.
• Surgery to repair retinal detachment.
• Treatments to improve breathing.

How can I prevent spondyloepiphyseal dysplasia congenita?

There’s no way to prevent SEDC. Some families who know they carry the COL2A1 mutation may choose not to have children.

What is the outlook with spondyloepiphyseal dysplasia congenita?

Outcomes with SEDC vary widely, depending on the signs and symptoms and their severity.

The condition can significantly affect your mobility and ability to perform physical tasks. Many people with the condition eventually require surgical and medical treatments. But people with SEDC generally have normal intellectual development and a normal life expectancy.

How do I take care of myself or my child with SEDC?

If you or your child has SEDC, consider the following strategies to manage the condition:

• Attend all follow-up appointments and tests.
• Avoid contact sports and other activities that can lead to injuries, particularly to your head and neck. Unstable joints can be injured easily.
• Be careful when receiving anesthesia. Tell all your healthcare providers about your SEDC diagnosis. Some of your physical features can lead to complications during surgery.
• Consider talking to a counselor or attending a support group, which can teach you ways to cope with the condition.

What else should I ask my doctor about spondyloepiphyseal dysplasia congenita?

If you or your child has been diagnosed with SEDC, consider asking your healthcare providers the following questions:

• What parts of my body will SEDC affect?
• What specialists should I see?
• How often should I have follow-up appointments and tests?
• What treatments will I need?
• Is anesthesia safe for me?
• Can I pass this on to my kids?
• Should other members of our family have genetic testing?
• Do you know of any support groups that might help us cope?

A note from Cleveland Clinic

It can be scary to find out that your child has a genetic disorder that requires medical care. But your care team is part of your support system. They can help point you to support groups where you can share your experiences with other people who have rare genetic disorders.