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Crouzon Syndrome
(Craniofacial Dysotosis)
Pronounced: Krooz-on SIN-drom
by Rick Alan
En Español (Spanish Version)
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)
© 2011 Nucleus Medical Media, Inc.
Causes
Crouzon syndrome is a genetic autosomal dominant 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
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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 diagnose 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
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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:
Surgery
There are a number of surgeries used to treat the symptoms of Crouzon syndrome. These include:
Craniectomy involves removal and replacement of portions of the cranial bone. This surgery is done as early
as possible after birth to prevent pressure on and damage to the brain and to maintain a skull shape that is as
normal as possible.
Surgery to treat exophthalmos (protrusion of one or both eyeballs). This surgery is done directly on the eye
sockets or on the bones surrounding the eye sockets to help minimize exophthalmos.
Surgery to treat protruding lower jaw. This surgery is often very successful in normalizing the appearance of
the jaw by removing a portion of the jaw bone.
Surgery to repair a cleft palate.
Orthodontic Treatment
Braces and other orthodontic treatments are usually necessary to help correct misalignment of teeth.
Eye and Ear Treatment
An ophthalmologist (eye specialist) and otolaryngologist (ear, nose, and throat specialist) should monitor infants
and children with Crouzon syndrome. These specialists can check for problems and provide corrective treatment
as necessary.
Supportive Treatment
This includes special education for children with a mental deficiency or intellectual disability.
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.
RESOURCES:
Cleft Palate Foundation
http://www.cleftline.org/
Crouzon Syndrome
http://www.familyvillage.wisc.edu/lib_crouz.htm
National Institute of Dental and Craniofacial Research
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http://www.nidr.nih.gov/
Online Mendelian Inheritance in Man
http://www.ncbi.nlm.nih.gov/
CANADIAN RESOURCES:
The Centre for Craniofacial Care and Research at SickKids
http://www.sickkids.ca/craniofacial/
REFERENCES:
Abnormal timing in the prenatal ossification of vertebral column and hand in Crouzon syndrome. Am J Med Genet
. 2000 Feb 28.
Craniosynostosis syndromes (FGFR-related). GeneReviews at GeneTests, GeneClinics: Medical Genetics
Information Resource (database online). University of Washington, Seattle, 1997-2002 (updated weekly).
Available at: http://www.genetests.org. Accessed November 2004 .
Dalben Gda S, Costa B, Gomide MR. Oral health status of children with syndromic craniosynostosis. Oral Health
Prev Dent . 2006;4(3):173-9.
Perlyn CA, Morriss-Kay G, Darvann T, Tenenbaum M, Ornitz DM. A model for the pharmacological treatment of
crouzon syndrome. Neurosurgery . 2006 Jul;59(1):210-5.
The National Center for Biotechnology Information website. Available at: http://www.ncbi.nlm.nih.gov/ .
National Institute of Dental and Craniofacial Research website. Available at: http://www.nidcr.nih.gov/ .
Last reviewed December 2011 by J. Thomas Megerian, MD, PhD, FAAP
Last Updated: 12/30/2011
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