Crouzon Syndrome
Patient Information
Characteristics
Background and History
This disorder, first described in the early 20th century by a French neurologist, Louis E. O. Crouzon, belongs to a group of conditions known as ‘craniosynostoses’. Several subtypes have been described but many features overlap and the exact type a given patient has can be difficult to determine. Some patients have such mild disease that they would be considered unaffected by many people.
Clinical Correlations
Crouzon syndrome has primarily skull, facial, and ocular signs. Some of the bones in the skull do not form properly and, as a result, the skull is misshapen with a high forehead and a shortened front-to-back length. The bones in the midface are underdeveloped so that the cheeks may appear flat and the upper teeth are crowded and sometimes misplaced. The nose has a ‘beaked’ appearance, the upper lip may be short and the jaw seems large.
Because the eye sockets are shortened, the eyes often are prominent, and, sometimes so much so that normal blinking is inadequate to keep the globes moisturized. The eyes often do not appear straight (strabismus). When the pressure in the brain is high, the optic nerves can be damaged resulting in vision loss.
Genetics
Inheritance
This is an autosomal dominant disorder with a vertical inheritance pattern since affected parents often directly pass the mutation to their children.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission
Diagnosis and Prognosis
Crouzon syndrome patients can expect to live a normal life span. The cornea of the eye (clear windshield) must not be allowed to dry out and an ophthalmologist should monitor this. Dental problems can usually be successfully treated. Neurosurgical treatment may be required if the pressure inside the skull is too high.
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