Definition

Crouzon syndrome is a genetic disorder. It is one of many birth defects that results in abnormal fusion between bones in the skull and face. Normally, as an infant’s brain grows, open sutures between the bones allow the skull to develop normally. When sutures fuse too early, the skull grows in the direction of the remaining open sutures. In Crouzon syndrome, bones in the skull and face fuse too early. This results in an abnormally shaped head, face, and teeth.

Crouzon disease is believed to affect 1 in 60,000 people.

Normal Open Sutures in Infant Skull (Pink)

© 2009 Nucleus Medical Art, Inc.

Causes

Crouzon syndrome is a genetic disorder. It is caused by mutations (abnormal changes) of the FGFR2 (fibroblast growth factor receptor) or less commonly of the FGFR3 genes. These genes help regulate the development of limbs. A mutation in these genes may cause bones in the skull to fuse too early. Researchers continue to learn more about the links between mutations in these genes and the various types of craniosynostosis syndromes they cause.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Those most at risk for Crouzon syndrome are children of:

• Parents with the disorder
• Parents who do not have the disorder, but who carry the gene that causes the disorder.
• Fathers at an older age at the time of conception

Symptoms

The main signs and symptoms of Crouzon syndrome include:

• Flattened top and back of head
• Flattened forehead and temples
• Mid-face that is small and located further back in the face than normal
• Beaked-like nose
• Compression of nasal passages, often causing reduced airflow through the nose
• Large, protruding lower jaw
• Misalignment of teeth
• High-arched, narrow palate, or cleft palate

Other symptoms and complications that can result from Crouzon syndrome include:

• Hearing loss
• Deformity of middle ears
• Absence of ear canals
• Meniere’s disease]]> (dizziness, vertigo, or ringing in the ears)
• Vision problems
• Crossed eyes or involuntary eye movement
• Curvature of the spine
• Headaches
• Fuse joints (in some cases)
• Acanthosis nigricans (small, dark, velvety patches of skin)

Diagnosis

A doctor can usually diagnosis Crouzon syndrome at birth or in early childhood based on the patient’s physical signs and symptoms. Tests are taken to confirm the diagnosis. These may include:

• X-rays]]> —a test that uses radiation to take a picture of structures inside the body, especially bones
• ]]>MRI Scan]]> —a test that uses magnetic waves to make pictures of the inside of the body
• ]]>CT Scan]]> —a type of x-ray that uses a computer to make pictures of the inside of the body
• Genetic testing—tests to confirm mutations in the FGFR2 or FGFR3 gene, which may be used if the clinical findings are not sufficient to make a diagnosis

Treatment

There is no cure yet for Crouzon syndrome. Because the molecular cause is now known, scientists are exploring ways to block the processes that lead to early fusion of the sutures without affecting other important growth processes. These efforts are currently restricted to experimental animals, but human advances may be on the horizon.

Currently, many of the symptoms can be treated with surgery. In addition, orthodontic treatment, eye and ear treatment, and supportive treatment are usually needed. Good dental care is also an important aspect of managing the care of children with Crouzon syndrome.

Treatment may include:

Prevention

There is no known way to prevent Crouzon syndrome. If you have Crouzon syndrome or have a family history of the disorder, you can talk to a genetic counselor when deciding to have children.