Am I at Risk? The Genetics of Inheritable Diseases
Many people wonder whether they have a higher chance of getting an eye disease because of a parent’s experience with the condition. We want to walk you through the genetics of a few key inheritable eye conditions: Fuchs’ dystrophy, Glaucoma, Cataract, Nearsightedness, and Keratoconus.
Fuchs’ dystrophy is an inheritable disease that decreases the number of cells lining the eye’s surface, the cornea, which causes fluid buildup in the eye. People with Fuchs’ dystrophy may pass the disease to their children. If one parent has Fuchs’ dystrophy, and one of that person’s parents also had the disease, then the child has about a 50% chance of having the disease. Fuchs’ can also appear in patients whose parents did not have the disease. In this case, the probability that the person will carry on the disease to children is unknown.
Glaucoma is a disease that damages the optic nerve, and it is the leading cause of blindness in the United States. People who have first-degree relatives with glaucoma have a higher risk of getting glaucoma than people without a family history of the disease. Though glaucoma can affect anyone, people with African-American, Hispanic, or Asian descent have a higher risk of developing the disease. Because glaucoma can affect anyone, regular, comprehensive eye exams are important for monitoring eye health. As a patient becomes older, comprehensive eye exams should be completed more frequently.
A cataract is a clouding that occurs in the lens of the eye, and though painless, they can affect vision by limiting the amount of light that can enter the eye. Most cataracts occur because of people’s natural aging or injury, and people who develop them later in life do so because of a common stiffening and thickening of the lens, which causes the cloudiness. Cataracts can also develop from past surgeries, other eye conditions, or diseases such as diabetes. On rare occasions, infants and children can have congenital cataracts, which they are born with. Genetics, intrauterine distress, or intrauterine infection can cause these cataracts.
Nearsightedness, or myopia, happens when someone has blurred distance vision because of the long shape of the person’s eye. People generally become nearsighted before the age of 20. Myopia is a common condition, and about a third of Americans are nearsighted. Myopia develops because of a combination of genes and the environment. People whose parents have myopia have a higher probability of also having the condition, but environmental factors also influence its occurrence. People are able to function normally with myopia, as glasses, contacts, or laser vision correction can be viable solutions for improving distance vision.
Keratoconus is a condition where the front part of a person’s eye, the cornea, thins and becomes abnormally shaped, which distorts the person’s vision. Though heredity may play a role in keratoconus, less than 10 percent of patients with keratoconus have a family member with the disease. The likelihood that someone will develop keratoconus increases if the person is a fervent eye rubber or has specific conditions, such as Down syndrome, retinitis pigmentosa, and asthma.
Though genetics play a role in some eye conditions, other factors such as the environment also play a major role in determining whether you develop an eye condition. See your eye doctor regularly to ensure that your eyes are healthy and that you are on top of any concerns that may arise.