Crouzon Syndrome Frequently-Asked Questions (FAQs)
Originally Created by Thomas Head
I. The Basics
A. What is Crouzon Syndrome?
Crouzon Syndrome is a hereditary condition diagnosed based on a pattern of cranial and facial malformations. The basic identifiable sign of Crouzon Syndrome, present also in many similar disorders, is premature fusion of the sutures. Facial symptoms include exophthalmos (small eye sockets), midface hypoplasia, and vertically compressed nasal passages (giving the nose a "beaked" appearance). Non-craniofacial symptoms are also sometimes present.
Crouzon (usually pronounced "krooz-on") Syndrome is sometimes also called craniofacial dysostosis or Crouzon's disease, though these terms are no longer widely used.
B. When was it discovered?
A French surgeon by the name of Crouzon discovered what he described as a hereditary craniofacial condition. He wrote of his findings in a 1912 issue of the Bulletins et Memoires Societe Medicale des Hopitaux de Paris. The initial case consisted of a mother and child, both with Crouzon symptoms.
C. What are the basic symptoms?
A wide range of symptoms have been attributed to Crouzon Syndrome, but the standard craniofacial symptoms are: premature fusion of sutures, a "flat" sphenoid bone, exophthalmos (protruding eyes), a hypoplasic midface/small palate with subsequently compressed nasal passages, and a large jaw. Severity of all Crouzon symptoms varies from case to case.
Premature Fusion of Sutures
The basic, and usually most dangerous, effect of Crouzon Syndrome is premature fusion of the sutures. The two sutures involved are usually the two coronal sutures, although this is not always the case; when the two coronal sutures are the only two fused, this leads to an abnormally high forehead. The condition is usually referred to as acrocephaly. There have been cases, in Crouzon Syndrome, of a wide variety of sutural fusions.
Regardless of the type of cranial vault deformation, surgery is almost always necessary to allow the brain room to grow. There are, however, a wide variety of surgeries available which generally leave the patient with a relatively normal skull shape and full bone coverage.
In most cases of Crouzon Syndrome, the sphenoid bones (the temples) are "flattened". Although this is generally one of the criteria employed to diagnose Crouzon Syndrome, it is not usually a terribly noticeable or debilitating craniofacial symptom (despite its proximity to various sensitive craniofacial areas); it's a good thing, too, because it is virtually impossible to surgically correct.
The most obvious and distinctive facial symptom of Crouzon Syndrome is exophthalmos (protruding eyes). It is pretty much impossible to fully correct by surgery, although procedures exist to reduce its severity. Exophthalmos is probably the Crouzon symptom most likely to get a child teased on a playground, but is usually otherwise benign. Personal experience has taught this author that exophthalmos sometimes becomes less marked as the patient grows older.
In Crouzon Syndrome, the midface (maxilla and nasopharynx) does not naturally "grow out" as far as it does in most people; it's smaller and located slightly further back in the face. This, combined with the unusually large lower jaw (see below), causes the upper teeth to be out of alignment with the lower teeth. The size and location of the nasopharynx causes vertical compression of the nasal passages, often leading to a reduced airflow through nose breathing. The vertical compression of the nasal passages is generally referred to as "Croupert", because it occurs frequently both in Crouzon and Apert syndromes. Procedures exist to "pull out" the midface, although such procedures are fairly lengthy and complicated.
Another facial symptom common in Crouzon is the large jaw. This (by contrast) causes the midface hypoplasia to appear worse than it is, and also leads the lower teeth to be further out of alignment with the upper. The large jaw is probably the Crouzon symptom most easily correctable by surgery.
D. What are some other common symptoms?
Crouzon Syndrome frequently causes disorders related to auditory canals which may lead to hearing loss. Sleep apnea is also extremely common.
Once reported in textbooks as a condition unassociated with non-craniofacial deformities, it has now been linked to other symptoms as well. Among them are vertebral malformations (curvature or subluxation of the spine), digital fusion, and ankylosis of the elbow joints. Such symptoms are common and warrant a subcategory of Crouzon Syndrome, "Type II" (see below).
Various rare complications have been reported whose presence in Crouzon patients may or may not be coincidental (such as valve blockages, mitral valve disorders, eye disorders, respiratory dysfunctions, and serious spinal deformities). Specialists are still trying to isolate the symptoms caused by Crouzon Syndrome from symptoms caused by unrelated conditions.
E. What are "Type I" and "Type II"?
Type I Crouzon Syndrome consists only of craniofacial symptoms; Type II includes both craniofacial and non-craniofacial symptoms.
F. Is Crouzon Syndrome fatal?
Not as such. The premature fusion of sutures can cause life-threatening damage, but advances in surgical technique have significantly reduced the inherent dangers. With rare exceptions, Crouzon Syndrome does not interfere with basic body processes and should not reduce one's lifespan.
A. Can Crouzon Syndrome be inherited?
Yes. Current medical literature seems to have reached the consensus that a child, in a situation where one parent has Crouzon Syndrome, has roughly a fifty percent chance of being born with the condition.
It is interesting to note that Dr. Crouzon, in his initial 1912 report, labeled the disease "hereditary craniofacial dysostosis".
B. Can Crouzon Syndrome occur "spontaneously", without a family history of the condition?
Yes, and it frequently does. Statistics seem to suggest that Crouzon Syndrome occurs spontaneously in twenty-five to fifty percent of cases.
C. Has the gene for Crouzon Syndrome been found?
The author is still researching this, but one may find interesting articles addressing this very question in the past few years's issues of the medical journal Nature Genetics. It seems to be a topic of some debate, although most sources seem to agree that the gene for Crouzon Syndrome is located somewhere on chromosome 10 and not, as once believed, on chromosome 7. When this author is at least partially satisfied with a more specific conclusion, he will deal with this at greater length (with citations, of course).
III. Treatment and Surgery
A. What kind of surgery is used to treat...
...premature fusion of the sutures?
The premature fusion of the sutures is generally corrected as soon as reasonably possible after birth, to prevent potential brain damage. Depending upon the severity of cranial deformation, several options are available. Virtually all surgical options involve removal and replacement of the cranial vault to relieve pressure; the removal of cranial bone is called a craniectomy. Craniectomies may be partial (wherein only some bone, usually a strip, is removed from the skull and replaced) or full (wherein the entire skull is removed, fragmented, and put back in place to grow together). The latter is referred to as a morcellation craniectomy. Skull shape is maintained through external molds; thanks to a procedure invented twenty years ago, called lateral canthal advancement, one may have a partial or full craniectomy and still maintain a normal skull shape.
Exophthalmos is difficult to treat. Various procedures exist, however, which I will (perhaps naively) divide into two basic categories: orbital surgeries and non-orbital surgeries. Non-orbital surgeries are performed with minimal interference with the eye socket proper, focusing instead on the bone surrounding the eye socket. For example, surgery in which one grafts bone to the browline or cheekbone would not involve surgery in the orbits proper. Orbital surgery involves actually placing the eyes further back in the orbits or changing their position.
Often times exophthalmos is caused by prematurely fused shallow orbits; through surgery, the bone of the orbits can be removed and allowed to reossify. In some cases, however, the shallow orbits are due to a tight craniofacial structure and removing the orbital bones may accomplish little.
This author is not familiar with any surgery which claims to actually eliminate exophthalmos; rather, the surgeries offered seem to be designed to reduce its severity. Likewise, any surgery involving orbital reconstruction may put the optic nerves at risk and should be considered carefully.
...the large jaw?
As Crouzon symptoms go, the large jaw is remarkably easy to treat. Surgical advancements have led to a scarless lower jaw reduction wherein portions of the mandible are actually removed via incisions made inside the mouth. The jaw is then held together by wires and the bone allowed to heal.
...common Type II symptoms?
The author is still researching surgeries used to treat Type II symptoms, but hopes to finish this section within the very near future.
IV. Related Disorders
A. How is Crouzon Syndrome like/unlike...
Crouzon Syndrome and Apert Syndrome are remarkably similar. Both involve cranial vault fusion (usually of the same sutures, nontheless) and midface hypoplasia (leading to vertically compressed nasal passages which, because they occur in basically the same fashion in both conditions, are referred to as "Croupert"). Also noteworthy is the fact that they were both discovered by French surgeons, within six years of one another, and that the initial reports of both conditions were published in the same journal.
There are, however, some qualifying differences between the two conditions. Apert Syndrome is more likely to involve non-craniofacial deformations (digital fusion is extremely common); further, while most Crouzon cases are hereditary, most Apert cases are not. They are, nontheless, similar conditions and are often listed together in medical textbooks.
For more information about Apert Syndrome, check out Teeter's Page.
Like Crouzon Syndrome, Saethre-Chotzen involves premature cranial vault fusion. Whereas the premature synostosis causing Crouzon's maxillary hypoplasia is central to the face, however, Saethre-Chotzen's facial anomalies tend to be more localized and vary greatly from individual to individual. Rather than exophthalmos, Saethre-Chotzen patients tend to have "drooping" upper eyelids. Saethre-Chotzen is also marked by non-facial conditions such as fusion of skin tissue, short digits, and various skeletal malformations.
While Carpenter (Carpenter's) Syndrome was technically discovered in 1901, it was not widely diagnosed until 1966. It involves premature cranial vault synostosis, leading generally to severe acrocephaly (resulting very often in mental retardation). Varying eyelid and digital anomalies are also common.
Pfeiffer Syndrome involves premature cranial vault synostosis of both coronal sutures, whereas in Crouzon Syndrome other sutures may be the culprit. Like Crouzon Syndrome, however, Pfeiffer Syndrome causes midface hypoplasia. Pfeiffer Syndrome is also identified by unusually wide thumbs and fusion of the soft and/or connective tissue in the hands.
Waardenburg Syndrome involves a cleft palate, displacement of the eyelids, partial albinism, a broad septum, deafness, and various limb defects. Premature cranial vault synostosis is not, however, a common effect of the condition.
Treacher-Collins Syndrome (also known as Franceschetti-Klein Syndrome or mandibulofacial dysostosis) was first noted in 1846, although clear diagnostic criteria were not established until 1949. It is marked by maxillary and mandibular hypoplasia, outer ear malformations, and various eyelid malformations.
B. How common is sleep apnea in Crouzon Syndrome?
A. "Can someone with Crouzon Syndrome live a 'normal' life?"
Contributed by Thomas Head (email@example.com)
Can Kate Moss live a 'normal' life?
I'm always intrigued by the "normal life" question. It's one that I'd asked myself a little when I was growing up, but didn't really put much thought into answering until I encountered other folks who have Crouzon Syndrome. It occured to me that so much of our lives revolves around appearance...and linear standards of attractiveness vs. unattractiveness aside, one thing's pretty much for certain: people who have Crouzon Syndrome, no matter how much surgery they've had, will look like people who have Crouzon Syndrome. Period. There's no getting around this. That doesn't mean we'll be "ugly", and that doesn't even mean that our faces necessarily demand explanations. It just means that we're never going to look like Mel Gibson or Barbra Streisand, because Mel Gibson and Barbra Streisand don't have Crouzon Syndrome. In other words, what I've got affects my face. It changes the way I look. I can make the most of it, I can apologize for it, and I can have surgery on it -- but it ain't going anywhere.
So to those of you who are miserable if you don't look just like your average fine looking actor/actress, become your own fine looking actor/actress. You'll have to develop your personal style, at least until exophthalmos becomes gothic chic and people start creating it surgically to be fashionable, but facial differences have more to them than "ugliness". How do you think facial piercings looked until people "started looking good" (?) with them?
Oh, and toss away all that crap you read from plastic surgeons about self-esteem. They have every reason to be concerned about our self-esteem; that's where they get their paychecks!
One more thing: you have no reason to feel guilty about handing down Crouzon Syndrome. People have every right to have kids. There are folks with potentially fatal physical conditions who hand them down all the time. Eugenics is unfashionable, and for very good reason. Remember that half the cases of Crouzon represent fresh mutations, and the general consensus seems to be that it's better, as a kid, to have people in the family who've already been through what you have.
Be yourself. You're sure as hell not going to be anybody else...and why would you want to?
For more information about Crouzon Syndrome written by medical professionals,