SNP Shot: Genomic Insights

Keratoconus is an eye disorder where the cornea, the clear front part of the eye, becomes thin and bulges outward into a cone shape. This change in corneal structure progressively worsens, causing nearsightedness (myopia), irregular astigmatism (blurred vision not correctable with glasses), and potential vision impairment.

During an eye examination, doctors may observe other signs of keratoconus, such as a Fleischer ring. This ring is a yellow-to-brownish deposit of iron surrounding the iris (the colored part of the eye). Another sign is Vogt's striae, which are fine, vertical, white lines located in the deeper layers of the cornea.

Initially, keratoconus might affect only one eye. However, it usually progresses to involve both eyes, although the severity of the condition may differ between the two. As the disease progresses, corneal scarring can develop, often due to prolonged contact lens wear or excessive eye rubbing on the abnormally thin cornea.

The typical onset of keratoconus is during adolescence, and the condition slowly worsens until the individual reaches mid-adulthood, at which point the corneal shape tends to stabilize.

Inheritance:

In the majority of instances, keratoconus arises spontaneously without any family history of the condition. However, familial cases do exist. Keratoconus can be inherited in an autosomal dominant manner, meaning that inheriting only one copy of a mutated gene is enough to cause the disorder. In such cases, an affected individual typically has a parent with the condition. However, some individuals with the gene mutation might not develop the disorder, a phenomenon known as reduced penetrance. Keratoconus can also be inherited in an autosomal recessive manner, which requires inheriting two copies of the mutated gene, one from each parent. While the parents of an individual with autosomal recessive keratoconus each carry one copy of the altered gene, they usually do not exhibit any signs or symptoms of the condition themselves.