Did you know genetics play a role in up to 7 out of 10 age-related macular degeneration (AMD) cases? You may be at a higher risk of AMD if you have certain gene mutations (variants) or close family members with this eye disease. Although genetics influence your chances of developing AMD, they’re not the only factor in your risk.

In this article, we’ll discuss the role of genetics and family history in AMD. We’ll also briefly touch on risk factors you can control to maintain your eye health. Talk to your ophthalmologist (eye doctor) to learn more about your AMD risk.

AMD Is Partially Due to Genetics

Your genes are responsible for your characteristics — height, hair color, and risk of certain diseases. Everyone inherits their genes from their parents. You have two sets of chromosomes, one from your mother and one from your father. Your genes are found on your chromosomes. They act as instruction booklets for building proteins that perform jobs in your cells.

Many genes have variants or permanent changes within their instructions. Some variants may be found in groups of people with a disease. According to the American Academy of Ophthalmology (AAO), there are a few gene variants we know about that may raise the risk of AMD.

Having a gene variant doesn’t guarantee you’ll develop a disease like AMD. It just means you’re at a higher risk of having it at some point in your lifetime.

Researchers have done genome-wide association studies (GWAS) to find AMD-related genes. These studies examine the genes of large groups of people with a disease. The researchers look for any similar variants that may be related. So far, GWAS have found more than 30 genes that raise the risk of developing this eye disease.

The HTRA1 and ARMS2 Genes and AMD

The HTRA1 gene provides instructions for making the HTRA1 enzyme. This specialized protein breaks large proteins into smaller ones. HTRA1 is important for breaking down other proteins in the extracellular matrix. The extracellular matrix surrounds cells and tissues to give structure and support.

Some studies suggest that variants in the HTRA1 gene may cause drusen to form. Drusen are yellow deposits made of proteins and lipids (fats) that form in the retina, which is the innermost layer of the eye. These deposits are usually a sign that someone has AMD. HTRA1 gene variants may also cause inflammation in the extracellular matrix, affecting the eyes.

The ARMS2 gene is found next to the HTRA1 gene on the same chromosome. We know that the ARMS2 protein is found in the retina, but researchers aren’t quite sure what it does. Because HTRA1 and ARMS2 are next to each other, they may both play a role in AMD. It’s hard to tell if variants in one or both genes are to blame. More research is needed to figure out their roles.

Complement Cascade Proteins and AMD

The complement system is a complex part of your immune system. It’s made of several proteins that work together to protect you from bacteria and viruses. Some studies show that an overactive complement system creates too much inflammation. The extra inflammation attacks the retina in the eyes, leading to central vision loss in AMD.

Certain variations in your complement cascade genes may raise the risk of AMD. These genes provide instructions to make the proteins complement factor B and factor H. New medications known as complement inhibitors work by blocking the complement system to treat AMD.

Can You Get Genetic Testing Done for AMD?

At this time, the AAO doesn’t recommend genetic testing for AMD. There currently aren’t any gene therapies available for treating AMD, so there isn’t a reason to get testing done.

Doctors and researchers are still learning more about which genes play a role in this disease. Even if you were to get tested, it likely wouldn’t give you any useful information. Genetic testing may play a large role in the diagnosis and treatment of AMD in the future as we learn more.

Having a Family History of AMD Raises Your Risk

You share your genetics with many close family members — including your biological parents and siblings. Remember, half of your DNA comes from each parent. Your siblings have the same DNA, but it’s matched in different ways to make new combinations. This is why you may look like one sibling and not another.

Even so, you’re at a higher risk of developing AMD if you have a family history. Having a parent or sibling with AMD gives you a 50 percent chance of developing the disease. Just because you have a family history doesn’t mean you’re guaranteed to have AMD.

Be sure to talk to your parents and siblings about their eye health. If they have AMD or if you know it runs in your family, let your eye doctor know. They’ll encourage you to get regular eye exams to monitor your eye health.

You Can Control Other Risk Factors of AMD

Unfortunately, you can’t control your genetics to lower your risk of AMD. However, there are certain health conditions and environmental factors that are known to influence this disease. Smoking is a key risk factor for AMD. People who smoke are four times more likely to develop AMD than those who don’t.

Your genetics and lifestyle choices influence each other more than you think. We know that people with HTRA1 variants are at a greater risk of AMD. Studies show that people who smoke and have HTRA1 variants are 20 times more likely to develop AMD compared to those with these variants who don’t smoke.

Your cardiovascular health also affects your eye health. If you have high blood pressure, you’re at an increased risk of developing AMD. A high body weight (obesity) also contributes to AMD development.

Talk to Your Doctor About Your AMD Risk

If you’re concerned about your risk of developing AMD, talk to your eye doctor about screening. They can take pictures of your retina to look for signs of AMD over time. It’s a good idea to get this testing done every time you visit for a regular eye exam.

You can also ask your eye doctor about factors within your control and what steps you can take to lower your AMD risk. They may recommend making healthy lifestyle choices like eating a nutritious diet with antioxidants and quitting smoking. Controlling your blood pressure and weight with diet and exercise also helps protect against eye diseases. Wearing sunglasses and a hat protects your eyes from the sun’s harmful ultraviolet rays as well.

Be sure to make an appointment with your eye doctor right away if you notice any new vision changes or vision loss. They’ll be able to diagnose and start your treatment to avoid any further eye damage.

Talk With Others Who Understand

On myAMDteam, the social network for people with age-related macular degeneration and their loved ones, members come together to ask questions, give advice, and share their stories with those who understand life with AMD.

Are you or a family member living with AMD? Do you have any risk factors for AMD? Share your experiences in a comment below or on your Activities page.