Congenital stromal corneal dystrophy

Congenital stromal corneal dystrophy is an inherited eye disorder. This condition primarily affects the cornea, which is the clear outer covering of the eye. In people with this condition, the cornea appears cloudy and may have an irregular surface. These corneal changes lead to visual impairment, including blurring, glare, and a loss of sharp vision (reduced visual acuity). Visual impairment is often associated with additional eye abnormalities, including "lazy eye" (amblyopia), eyes that do not look in the same direction (strabismus), involuntary eye movements (nystagmus), and increased sensitivity to light (photophobia).

Congenital stromal corneal dystrophy is probably very rare; only a few affected families have been reported in the medical literature.

Congenital stromal corneal dystrophy is caused by mutations in the DCN gene. This gene provides instructions for making a protein called decorin, which is involved in the organization of collagens. Collagens are proteins that strengthen and support connective tissues such as skin, bone, tendons, and ligaments. In the cornea, well-organized bundles of collagen make the cornea transparent. Decorin ensures that collagen fibrils in the cornea are uniformly sized and regularly spaced.

Mutations in the DCN gene lead to the production of a defective version of decorin. This abnormal protein interferes with the organization of collagen fibrils in the cornea. As poorly arranged collagen fibrils accumulate, the cornea becomes cloudy. These corneal changes lead to reduced visual acuity and related eye abnormalities.

Read more about the DCN gene.

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

In most cases, an affected person has one parent with the condition.