Crouzon Syndrome: Definition and Prognosis (Is it Serious?)

crouzon syndrome crouzon syndrome

At birth, the human being is born with an immature cranium formed of bones which have not yet reached their total closure. This anatomical condition allows the brain to grow and mature with age.

However, in rare cases, the welding these bones is done prematurely and this anomaly affects both the morphology of the brain and the face giving an appearance of malformation very characteristic. This is what defines the Crouzon's syndrome, a pathology rare genetics which affects approximately 1/50000 births.

What is Crouzon syndrome?

The name of Crouzon syndrome comes from the French neurologist Louis Edouard Crouzon, who described it for the first time at the beginning of the 20th century.

It's about a congenital malformation (present at birth), of genetic origin, linked to a immigration of the FGFR2 gene located on chromosome 10. On the anatomo-pathological level, this anomaly is characterized by a premature suturing of the bones of the skull (craniosynostosis), causing atypical growth of the brain and the organs that make up the face.

The child carrying this syndrome can manifest more or less serious neurological and functional complications as he grows up. However, these complications can be prevented or significantly reduced as long as the disease is diagnosed and treated in time.

From an epidemiological point of view, Crouzon syndrome is the most common rare genetic abnormality affecting the bones of the skull.

How to recognize Crouzon syndrome?

It is obvious that Crouzon syndrome is identified at birth, but most of the symptoms defining this syndrome are evident during the first year of life.

In general, infants who are affected present a picture essentially bony, which manifests itself, most often, by:

  • A brachycephaly: which corresponds to an enlargement of the skull at the parietal level and a flattening of the back of the head, giving the impression that the back of the head is higher than the forehead.
  • A proptosis: term designating an excavation of the eyes which results from the premature ossification of the bones composing the eyeballs. This protrusion could induce vision problems in the child.
  • A Horbital hypertelorism ou ythem discarded : symptom characterized by an abnormal increase in the distance separating the two eyes. This malformation is observed in many genetic diseases such as trisomy 18, Apert syndrome, etc.
  • Un beak-shaped nose : if not surgically treated, this symptom may be responsible for breathing difficulties, ranging from simple respiratory discomfort to obstructive sleep apnea syndrome.
  • A pprojection of the mandible (lower jaw) forward, which is more evident when paired with a upper jaw hypoplasia. This changes the anatomy of the oral cavity and sometimes affects mastication and phonation.

In addition, other less common symptoms and complications may occur inconsistently in children with Crouzon. Among these signs are:

  • Personalized hearing problems: 55% of children with Crouzon syndrome have a greatly reduced acoustic capacity due to the fact that they were born without auditory canals.
  • Personalized joint problems : at the cervical level, reported in 30% of patients.
  • Acanthosis Nigricans: this dermatological condition, which is most often a marker of insulin resistance in children, can also be included in Crouzon's syndrome, where it is characterized by thicker and darker skin.

What are the causes of this condition?

As mentioned in the definition, Crouzon syndrome is a genetic disease whose origin resides on the “FGFR2” gene where there is "error" or "mutation".

This gene is involved in controlling the production of proteins responsible for bone development and growth. Its mutation will therefore cause a acceleration of the ossification process of all or part of cranial sutures.

The mode of transmission of the disease is autosomal dominant. That is to say, a person carrying the mutation has a 50% risk of transmitting it to their future children.

What about the prognosis?

You should know that this disease, although it is incurable, is generally always good prognosis ! A child with this syndrome can lead an almost normal life, provided that his illness is diagnosed as early as possible and surgery is done in time.

In addition, if it can be reassuring, apart from the various complications that we have already mentioned above, a child with this syndrome has intellectual capacities similar to those of a healthy individual. The cognitive faculties et intellectual are not affected.

Treatment of Crouzon syndrome 

Although there are several studies and researches that have been conducted with the aim of genetically curing Crouzon syndrome, none have resulted in human trials.

The treatment of this disease is therefore essentially symptomatic, and aims to prevent its complications and thus improve the quality of life of the affected child.

For a better prognosis of the disease, the child must benefit from a multidisciplinary care, involving professionals from different specialties, such as general practitioners, paediatricians, craniofacial surgeons, speech therapists, psychologists or child psychiatrists, etc.

The main therapies are:

surgery 

Most children with this syndrome are candidates for surgery because it represents one of the most important steps in their care.

It allows them to correct their craniofacial dysmorphism and, thus, will give their brains the chance to develop as normally and with as few complications as possible.

One of these interventions is the cranioplasty which surgeons use to treat or prevent a possible hydrocephalus, and also lighten the signs byintracranial hypertension (nausea, vomiting, headache, etc.).

Similarly, surgery of the nasal passages and oral cavity appears to be equally important in order to prevent respiratory problems such as sleep apnea.

Exophthalmos can also be treated surgically, this will not only improve the aesthetic side of the child, but will also minimize the risk of drying and infection of the eyes.

Maxillofacial interventions to improve the protrusion of the mandible and the deformity of the upper jaw.

In the face of major respiratory problems, a tracheotomy can be done urgently.

Please note: : it should be noted that the best time to resort to surgery (cranioplasty) is the first 12 months of life, since at this age the bones are more easily modeled and adapt better to surgical corrections. Nevertheless, the risk of recurrence of the sutures is all the higher as the age of the child is low.

Speech therapy

The role of the speech therapist consists in minimizing the complications linked to malformations of the phonatory apparatus. It can help the child to swallow safely, teach them to improve their language and breathing. In some cases where there is an associated cognitive impairment, the speech therapist may opt for the appropriate therapy.

occupational therapy

This therapeutic approach deals primarily with problems of eating, dressing, learning to write, emotional management, as well as other personal care related to activities of daily living.

Psychotherapy

A child diagnosed with a rare pathology such as Crouzon's syndrome runs the risk of encountering socio-affective and emotional problems in childhood or later in adulthood that will only accentuate his suffering. It is therefore essential to focus on the mental health and well-being of these patients, but also of their parents, in order to help them better care for their children with Crouzon syndrome.

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