A rare genetic disorder called Crouzon syndrome affects the development of the skull and face. It is one of the most common forms of craniosynostosis, a condition that prevents normal growth of the skull and face. There are a number of physical characteristics associated with Crouzon syndrome, including wide-set eyes, bulging eyeballs, a small nose, an underdeveloped jaw, and a cleft lip or palate.
In addition to vision problems, hearing loss, breathing difficulties, and hydrocephalus, it can also cause complications. As a result of a mutation in the FGFR2 or FGFR3 genes, which control bone growth, Crouzon syndrome can be inherited or caused by a new mutation. It is treated by undergoing several surgeries to correct the skull and facial abnormalities, as well as treating any associated problems associated with Crouzon syndrome.
In Crozon syndrome, there is a change or mutation in the FGFR2 or FGFR3 genes that cause the bones to grow and divide prematurely. These genes make proteins that signal the cells to grow and divide. The skull bones fuses prematurely when these genes are mutated because they cause the cells to grow and divide too much or too quickly. In addition to affecting the shape and size of the head and face, it also affects other structures such as the eyes, nose, ears, and teeth.
Parents who have Crouzon syndrome or carry the mutated gene can pass on the condition to their children. This is called autosomal dominant inheritance, which means that only one copy of the mutated gene is enough to cause the disorder. A parent with Crouzon syndrome has a 50% chance of passing it on to their children. Crouzon syndrome can also be caused by a new mutation occurring in the egg or sperm cell before conception. About half of the cases of Crouzon syndrome are caused by de novo mutations, which are not inherited from the parents. The risk of having a de novo mutation increases with the age of the father, especially if he is over the age of 40 to 45.
The symptoms of Crouzon syndrome vary from person to person, depending on the severity and extent of the skull and facial abnormalities. The most common symptoms of Crouzon syndrome are:
Wide-set eyes (hypertelorism)
Bulging eyeballs (proptosis)
Crossed eyes (strabismus)
Protruding forehead
Small, beak-shaped nose
Underdeveloped jaw
Cleft lip and/or palate
These physical features can cause various problems, such as:
Vision problems, such as blurred vision, double vision, or loss of vision
Dental problems, such as crowded teeth, malocclusion, or tooth decay
Hearing loss, due to abnormal development of the ear canal or middle ear
Breathing problems, due to narrow nasal passages or obstructive sleep apnea
Hydrocephalus, which is a buildup of fluid in the brain that can cause increased pressure, headaches, nausea, vomiting, or seizures
Rarely, intellectual disability, due to brain damage from increased pressure or lack of oxygen
Some people with Crouzon syndrome may also have other health conditions, such as heart defects, skin disorders, or neurological problems.
Rouzon syndrome is typically diagnosed at birth or in early childhood, based on the characteristic appearance of the head and face. The diagnosis can be confirmed by genetic testing, which can identify the mutation in the FGFR2 or FGFR3 gene. Genetic testing can also be used to determine inheritance patterns and the likelihood of recurrences.
Other tests that may be done to evaluate the extent and severity of Crouzon syndrome include:
X-rays, CT scans, or MRI scans, to examine the structure and shape of the skull and face
Eye exams, to check the vision and eye alignment
Hearing tests, to assess the hearing function and ear anatomy
Sleep studies, to monitor the breathing and oxygen levels during sleep
Lumbar puncture, to measure the pressure and fluid in the brain
As part of the treatment for Crouzon syndrome, skull and facial deformities are corrected and complications are prevented or treated. There are usually several specialists involved in the treatment, including craniofacial surgeons, neurosurgeons, ophthalmologists, otolaryngologists, orthodontists, and speech therapists.
The main treatment for Crouzon syndrome is surgery, which can be done at different stages of the child's growth and development. The goals of surgery are to:
Relieve the pressure on the brain and allow normal growth of the head
Improve the appearance and function of the face and eyes
Correct the cleft lip or palate and improve the speech and feeding
Align the teeth and jaws and improve the bite
Repair any heart defects or other anomalies
The types and timing of surgery depend on the individual needs and preferences of the child and the family. Some of the common surgeries for Crouzon syndrome are:
Cranial vault remodeling, which is done in infancy to reshape the skull and create more space for the brain
Frontofacial advancement, which is done in early childhood to move the forehead and midface forward and improve the eye position and breathing
Le Fort III osteotomy, which is done in late childhood or adolescence to move the upper jaw and nose forward and improve the facial balance and bite
Distraction osteogenesis, which is a technique that uses a device to gradually stretch the bones and soft tissues of the face and create more space and symmetry
Facial reconstruction, which is done to improve the appearance and function of the nose, ears, and lips
Other treatments that may be needed for Crouzon syndrome include:
Glasses, contact lenses, or eye surgery, to correct the vision and eye alignment
Hearing aids, cochlear implants, or ear surgery, to improve the hearing and ear function
Dental braces, implants, or crowns, to improve the dental health and appearance
Speech therapy, to help with the speech and language development
Shunt placement, to drain the excess fluid from the brain and treat hydrocephalus
Crouzon syndrome cannot be prevented, as it is a genetic disorder that occurs randomly or is inherited from a parent. However, some steps that can be taken to reduce the risk of having a child with Crouzon syndrome are:
Genetic counseling, which can provide information and guidance about the inheritance pattern, recurrence risk, and testing options for Crouzon syndrome
Prenatal testing, which can detect the mutation in the FGFR2 or FGFR3 gene in the fetus or the placenta
Preimplantation genetic diagnosis, which can screen the embryos for the mutation in the FGFR2 or FGFR3 gene before implantation in the uterus
Adoption or donor egg or sperm, which can avoid passing on the mutation in the FGFR2 or FGFR3 gene to the child
