Crouzon syndrome is a rare genetic disorder characterized by premature closure
of cranial sutures, exophthalmos and mid facial hypoplasia. Crouzon syndrome
occurs in approximately 1 in 25,000 births world wide and 16.5 per 1,000,000
live births in United States. It makes up approximately 4.8% of all cases of,
craniosynostosis, making it the most common syndrome within the craniosynostosis
group. It may be transmitted as an autosomal dominant genetic condition or appear
as a mutation .No known race or sex predilection exists (Cohen
and Kreiborg, 1992). The majority of the patients with Crouzon syndrome
have mutations in the extracellular immunoglobulin III domain of the Fibroblast
Growth Receptors 2(FGFR2)gene (Jabs et al., 1994).
The differential diagnosis of Crouzon syndrome includes Apert syndrome, Pfeiffer,
Jackson-Weiss, Carpenter and Saethre-Chotzen syndrome. Crouzon syndrome is distinguishable
from other craniosynostosis syndromes by lack of hand and/or foot abnormalities
(Bowling and Burstein, 2006). Multiple staged surgeries
are the general treatment plan for patients with Crouzon syndrome (Posnick
and Ruiz, 2000). In this article, we present a case of Crouzon syndrome
in a boy aged 7 years.
A 7 year old boy who had come for routine dental check up, was referred to the Dept of Oral Pathology for evaluation of dysmorphic features. On general examination the boy was of a short stature, had wide nasal bridge (hypertelorism) and mild exophthalmos (Fig. 1). The boy also complained of recurrent headaches and transient visual obscurations. The patient did not have any digital abnormalities or hearing deficit. Intraoral examination revealed high arched palate, hypo plastic maxilla leading to pseudo prognathism of mandible and class III malocclusion. No dental aplasia was present. On inquiring the mother reported that she had delivered when she was 35 years old. History revealed that these features started developing since he was a child and the severity gradually increased over a period of time. There was no significant positive family history. The patient was evaluated by an Opthalmologist in view of visual complaints which revealed papilloedema suggestive of raised intracranial pressure. Taking into consideration the above mentioned findings, following investigations were done.
3D Volume rendered images of the skull showed fusion of the coronal and the
sagittal sutures, prominent convolutional markings suggestive of copper beaten
appearance, shallow orbits and widened intercanthal distance (Fig.
2, 3, 5).
CT scan Brain showed prominent convolutions in the inner table of the skull
The overall radiological features confirmed the diagnosis of Crouzon syndrome.
The case was referred to:
||Neurosurgery department in view of the raised intracranial
pressure and craniosynostosis and the procedure of suturectomy with cranial
morcellation was advised
||Orthodontic dept for correction of malocclusion
|| Shows mild exophthalmos and hypertelorism
|| 3D Skull showing fusion of the coronal sutures
|| 3D Skull showing fusion of the sagittal and the coronal sutures
|| CT scan demonstrating convolutions on the inner calvarium
of the Skull
|| 3D Skull showing a copper beaten appearance
Octave Crouzon (1874-1938), a French neurologist, in 1912, described the hereditary
syndrome of craniofacial synostosis in a mother and son. He described the triad
as skull deformities, facial anamolies and exophthalmos now known as Crouzon
syndrome. It is an autosomal dominant disorder with complete penetrance and
variable expressivity (Jabs et al., 1994; Bowling
and Burstein, 2006).
The cause is attributable to mutations in the fibroblast growth factor receptor-2
(FGFR2)gene which is mapped to chromosome locus 10q25-10q26,but exhibits locus
heterogeneity with causal mutations in FGFR-2 (Crouzon syndrome) and FGFR3 (Crouzon
syndrome with Acanthosis nigricans) in different affected individuals (Jabs
et al., 1994).
The most common ocular abnormalities are shallow orbits, ocular proptosis,
orbital hypertelorism, strabismus, papilloedema, optic atropy, exoposure keratitis
and visual loss. There also have been rare occurances of nystagmus, iris coloboma,
aniridia, anisocoria, microcornea, megalocornea, cataract, ectopia lentis, blue
sclera, glaucoma and luxation of the eye (Bowling and Burstein,
Headaches and seizures are attributable to elevated intracranial pressure.
Conductive hearing loss is common owing to ear canal steinosis or atresia. Upper
airway obstruction develops secondary to septal deviation, mid nasal abnormalities,
choanal abnormalities and nasopharyngeal narrowing and can lead to acute respiratory
distress. Acanthosis nigricans is the main dermatological manifestation in 5%
cases of Crouzon syndrome (Cohen, 1975).
In the mouth, short upper lip, hypoplastic maxilla, relative mandibular prognathism,
malocclusions and v shaped maxillary dental arch have been reported, as has
narrow, high, or cleft palate and bifid uvula (Chen, 2004).
Apert syndrome, Pfeiffer syndrome, Carpenter syndrome, Saethre-Chotzen syndrome
are the commonest differential diagnosis to Crouzon syndrome (Bowling
and Burstein, 2006).
Radiographs, Magnetic Resonance Imaging (MRI) scans, genetic testing, X-rays and CT scans can be used to confirm the diagnosis. Ultrasonic prenatal diagnosis of Crouzon syndrome has been reported, however molecular testing is more accurate and reliable than ultrasonography. C.T scan brain shows signs of raised intracranial pressure, fusion of coronal and sagittal sutures and 3D images will reveal copper beaten appearance.
Preimplantation genetic diagnosis for Crouzon syndrome by blastomere biopsy
samples from cleavage-stage embryos may be detected by mutational analysis (Abou-Sleiman
et al., 2002).
The treatment is multidisciplinary and multiple staged surgeries are recommended
(Posnick and Ruiz, 2000). .Early craniectomy
with frontal bone advancement is most often indicated to prevent or treat increased
intracranial pressure. If necessary, midfacial advancement and jaw surgery can
be done to provide adequate orbital volume, reduce the exophthalmos and correct
the occlusion to appropriate functional position. Prognosis depends on the severity
of malformations. Innovations in craniofacial surgery have enabled patients
to achieve their full potential by maximizing their opportunities for intellectual
growth, physical competence and social interaction.
Crouzon syndrome should be managed as early as possible as it results in poor cosmetic appearance and results in other complications like mental retardation, airway obstruction and decreased visual acuity as the age advances. With proper treatment, these patients can be productive and active members of the main stream society.