Corneal Dystrophy, Congenital Stromal
Patient Information
Characteristics
Background and History
There are many hereditary disorders that impact the cornea, the clear windshield at the front of the eye. Most of them are manifest primarily in adulthood but this is one that is primarily evident in infancy. All of these cause some decrease in clarity of the cornea and consequently patients experience loss of clear, sharp vision.
Clinical Correlations
Congenital corneal degeneration (dystrophy) of the type described here is usually evident in infancy. Small spots of fluffy, flaky deposits throughout the cornea produce a diffusely cloudy appearance. With progression of these, vision loss can be severe enough to require transplantation with a clear donor cornea, in some as early as 6 years of age. Some patients experience light sensitivity and occasionally the corneal surface develops defects similar to scratches which are highly painful and slow to heal. Crossing of the eyes and glaucoma sometimes occur as well.
No systemic abnormalities are associated with this disorder.
Genetics
Inheritance
This is a rare autosomal dominant disorder in which the disease is passed directly from parent to child creating a vertical pattern of inheritance. Each child of an affected parent has a 50% chance of inheriting this disorder.
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
This corneal dystrophy can be diagnosed by an ophthalmologist. Some progression occurs and there is considerable variation among individuals. The end result may be sufficient clouding of vision that a corneal transplant is required to restore clear vision at an average of 20 years of age although transplants have been necessary as early as 6 years. All patients must be checked for glaucoma and treated appropriately.
Web Resources
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