What is Crouzon syndrome?
In Crouzon syndrome, certain bones in the skull fuse too soon. This process is called craniosynostosis. There are other effects of this condition and ways to manage them.
This article explores the symptoms, treatments, and outlook for Crouzon syndrome.
What are the symptoms?
Crouzon syndrome causes abnormalities in the shape of the head and face and may be apparent at birth.
Image credit: KateVUk, (2018, April 13)
Craniosynostosis is not usually associated with a genetic syndrome. In the rare case that it is caused by genetics, the condition is likely to be Crouzon syndrome.
It affects about 16 in every million babies that are born.
Crouzon syndrome causes premature fusion of certain bones in the skull and impacts the shape of a person's head and face.
Signs of Crouzon syndrome include:
- abnormal face shape
- shallow mid-face, which may lead to breathing difficulties
- high forehead
- wide-set, bulging eyes
- shallow eye socket, which may lead to vision problems
- eyes that point in different directions (strabismus)
- a small beak-like nose
- underdevelopment of the upper jaw which may lead to trouble eating
- dental problems
- low-set ears
- hearing loss with possible narrow ear canals
A less common sign is an opening in the roof of the mouth (cleft palate) or lip (cleft lip).
For some children symptoms are severe, for others they are milder. The condition affects each person differently.
It may lead to increased pressure in the skull (intracranial pressure), which can affect brain development and cause learning difficulties.
Another complication is breathing difficulties, which may be life-threatening if left untreated.
Anyone with Crouzon syndrome who is at risk from intracranial pressure and breathing difficulties may require surgery.
This section explores genes and how they affect the bones in the head:
A mutation in the genes causes Crouzon syndrome, which may be passed from parent to child.
Crouzon syndrome is genetic. It is not caused by anything that happens during pregnancy.
The condition is caused by mutations in a gene called FGFR2. As an embryo grows, this gene controls when immature cells become bone cells.
In Crouzon syndrome, a mutation in the FGFR2 gene affects the FGFR protein, causing it to behave abnormally in certain growing bones in the skull.
This leads to the premature fusing of the fibrous joints (sutures) between these bones.
Someone with Crouzon syndrome has a 50 percent chance of passing the condition on to their child.
Crouzon syndrome is not always inherited. Some babies are born with the condition and are the first in their families to have the syndrome. When this happens, it is called a de novo mutation.
Symptoms typically appear in the first year of a child's life. Sometimes, the symptoms will progress until the child is 2 or 3 years old. Other times, the condition is apparent at birth.
If a doctor suspects Crouzon syndrome, they will carry out a physical examination and ask questions about the family's medical history.
A doctor may carry out further tests including:
- magnetic resonance imaging (MRI) scans
- computed tomography (CT) scans
- genetic testing
Surgery may be performed during infancy to ensure the brain has room to grow.
Crouzon syndrome affects every child differently.
Treatment of Crouzon syndrome may include surgery. This is to improve symptoms, prevent complications, and help physical and mental development.
If the fused sutures are causing intracranial pressure, this may lead to brain injury.
This is treated with craniofacial or open vault surgery.
The purpose of surgery is to ensure there is enough space in the head for the brain to grow. It may also improve the appearance of the child's face and head.
If a person is experiencing breathing problems due to facial abnormalities, they may require a tracheostomy, which is a surgical procedure to make an opening in the windpipe to help them breathe.
As well as surgical treatments, people with Crouzon syndrome and their families may benefit from genetic counseling and support. These therapies often help them to cope with the psychological effects of living with a genetic condition.
Research into how to prevent the genetic mutation that causes Crouzon syndrome is ongoing.
A 2006 study using animal cells reported on a potential treatment that shows promise for prevention. This treatment aims to prevent sutures in the skull fusing in the womb.
This treatment is not yet fully developed or tested in animals or people.
Once cranial abnormalities have been treated surgically, there is a reduced risk of complications.
After treatment, most children with Crouzon syndrome go on to live healthy lives.
With treatment, the condition does not affect life expectancy.