Woman meeting with her doctor

Understanding Your Personal and Genomic Health: An Interview with Genome Medical

A few months ago, we partnered with Genome Medical to offer LunaDNA members access to their network of clinical genomic specialists to dig deeper into their health and DNA information.

Today, we’re chatting with Sheryl Walker, MS CGC to take a deeper look into the services they offer and how understanding your genetic makeup can help kickstart your health journey.

LunaPBC: Hi Sheryl Walker, MS CGC. Thanks for taking the time to chat with us today and share more about the amazing work you’re doing at Genome Medical. We’re excited to be partnering with you. In a nutshell, can you tell us more about Genome Medical and the services you offer to LunaDNA members?

Sheryl Walker, MS CGC, Genome Medical

Genome Medical: No problem, thank you for the opportunity! Genome Medical provides genetic counseling services by phone or video to individuals in all 50 states and has professionals with expertise in multiple areas of clinical care, including cancer, cardiology, reproductive, pediatric, pharmacy, and proactive genetic testing. LunaDNA members can schedule a one-on-one genetic counseling session in any of these areas to review their personal medical history and family medical history, discuss any appropriate diagnostic genetic testing, and get answers to specific questions they may have regarding previous test results. Diagnostic genetic testing can be informative for individuals with a diagnosis to guide treatment, aid in recommendations for future care, provide risk information for relatives, and more.  

LunaPBC: That’s wonderful. This is clearly beneficial for someone with health questions. It sounds like people can learn more about themselves and, importantly, take adequate preventative measures on their health journey. What if someone isn’t experiencing any health challenges? How might they benefit from speaking with a genetic counselor?

Genome Medical: That is an excellent question. As researchers continue to learn about how our genes impact our health and potential for disease, and as more consumers learn about the information their genes can provide, more individuals are seeking genetic information–including those who are healthy and unaffected by disease. While a person may not currently have a disease diagnosis, testing of their genes could reveal health risks and the potential for a future diagnosis. Many genetic diseases present earlier in life or family members will show signs and symptoms of a genetic disease that is being passed through a family, but this is not always the case. Many factors influence the manifestation of disease, including environment, lifestyle, age, and genetic factors. Even individuals who currently have a clean bill of health could have a risk for hereditary disease based on their family medical history or be found to have a genetic disease predisposition that may not show signs in standard health screenings. One such example is predisposition to hypertrophic cardiomyopathy, a hereditary disease that causes thickening of the heart muscle; this would not be identified unless a person was undergoing specific cardiovascular imaging. For several hereditary disorders, such as genetic predisposition to cancer risk, there are recommended screenings and management guidelines to help prevent a diagnosis and reduce risk. All individuals can benefit from reviewing their personal and family medical history with a genetic counselor. Even individuals who have no ‘red flags’ may be interested in and potentially benefit from clinical genetic testing and proactive health screening.  

LunaPBC: Last year, we commissioned the Harris Poll to conduct a survey across 2,000 Americans to better understand the relationship Americans have with consumer DNA test kits, including how informed they feel about how their DNA data will be used and general concerns with participation. We learned that roughly approximately one quarter of Americans are concerned about finding out they carry a genetic disease (24%) and that their insurance company could access their results (23%). What would you say to the population of people who have these concerns?

Genome Medical: As a genetic counselor, I feel strongly that genetic testing can be extremely beneficial, but also that genetic testing is a personal choice. I have found that patients will choose to learn about genetic testing at different times in their lives (e.g. not interested in their 30’s but become interested in their 40’s) and seek different amounts of genetic information. The discussion we have in their session helps determine how they want to proceed and what is going to be most beneficial for them. I think it is good to question one’s motivations for accessing genetic information and, even more importantly, to think about how one might use this information and how they would feel if they learned they carry a genetic predisposition to disease. Genetic testing does not change what already exists in our DNA, but the knowledge can change our awareness of predisposition and health risk.  

I often hear concerns about privacy and access to genetic information. Regardless of how genetic testing is being facilitated — be it through a research study, a direct-to-consumer DNA kit, or a diagnostic laboratory — it is important to know how your information and data are handled, accessed, stored, and what legal protections exist in relation to genetic information. The Genetic Information Non-Discrimination Act (GINA), enacted in 2008, protects individuals from discrimination in health insurance and employment based on genetic test results. Some states have additional protections beyond GINA. However, the federal protections do not extend to private life insurance, disability insurance, or long-term care insurance. More information on this federal law can be found at ginahelp.org. Genetic counselors discuss this information during appointments, as it can impact decision-making about genetic testing.   

The role of the genetic counselor is to help navigate these issues and decisions and explain risks and testing in a way that’s easy to understand. Genome Medical is proud to be able to provide this type of precision medicine care in a convenient and affordable way to their patients.  

LunaPBC: Knowledge is truly power. We often get asked, ‘Why would I use Genome Medical’s services when I can order a test on my own through companies like 23andMe and AncestryDNA?’ I’m sure you get these questions, too. How do you best answer this?

Genome Medical: It’s important to understand the difference between consumer and diagnostic testing. While there are many different direct-to-consumer (DTC) genetic tests available that a person can order themselves, diagnostic genetic testing can only be ordered by healthcare professionals like the genetic counselors and geneticists at Genome Medical. The testing performed by consumer companies typically uses SNP (single nucleotide polymorphism) analysis that looks at predetermined sites in your genes. Most diagnostic genetic testing, however, is performed using next-generation sequencing which looks comprehensive across all sites in the genes. You can think of it this way: if one of your genes was a book, SNP analysis is like reading a single page, whereas next-generation sequencing reads the entire book cover to cover. Further, consumer tests typically do not incorporate personal medical history or family medical history in their offerings. Genetic counselors study this important information alongside diagnostic genetic test results to provide personalized insights and recommendations on health risk. Lastly, most consumer companies report extremely limited, if any, information on inherited disease risk, and, if they did report a finding (whether cancer risk-related or otherwise), the finding absolutely needs to be confirmed through diagnostic genetic testing before making any changes to medical care. If an individual has a strong family history of cancer or cardiovascular disease, they should seek genetic counseling and diagnostic genetic testing.

LunaPBC: So, in short, there’s a significant difference. As we can imagine, your clinical team of 40+ medical geneticists, genetic counselors, primary care doctors, pharmacists, and other specialists — who can provide medical services in all 50 states — puts you at an advantage to reach a wide network of people. How soon can a member speak with one of your Genetic Counselors once they become interested?

Genome Medical: Appointments are very convenient. We can see individuals by phone or video. Interested LunaDNA members can typically speak with a genetic counselor within 24-48 hours (limited weekend appointments are available). 

LunaPBC: This is a great opportunity. Is there anything else that may be important for LunaDNA members to know that we may not have already covered?

Genome Medical: As mentioned earlier, I think everyone can benefit from a thorough discussion of their personal and medical family history. However, it is important to recognize that, like other areas of medicine, genetics is subdivided into different specialties. The genetic counselors at Genome Medical have different areas of expertise, so if an individual is interested in learning more about cancer risk and discussing inherited cardiovascular diseases, this may be best addressed in two separate appointments. In order for our genetic counselors to best tailor your session to fit your specific needs, it always helps to have as much information as possible before your scheduled appointment; this can include filling out our intake survey, indicating specific questions you want to address, and uploading previous genetic test results to our portal for review. The health information in your LunaDNA account can be easily forwarded ahead of your appointment. Our medical practice is driven by our desire to provide the best genetic healthcare experience possible. We look forward to hearing from your members!  

LunaPBC: Thanks for taking the time to chat with us, Sheryl Walker, MS CGC, and for supporting us to encourage our members to take control of their health and their data.

If you are interested in scheduling a consultation with a Genome Medical genetic counselor, you can do so here.

About Genome Medical
Genome Medical is a national telegenomics technology, services and strategy company bringing genomic medicine to everyday care. Through our nationwide network of genetic specialists and efficient​ Genome Care Delivery​ technology platform, we provide expert virtual genetic care for individuals and their families to improve health and well-being. We also help health care providers and their patients navigate the rapidly expanding field of genetics and utilize test results to understand the risk for disease, accelerate disease diagnosis, make informed treatment decisions and lower the cost of care. We are shepherding in a new era of genomic medicine by creating easy, efficient access to top genetic experts. Genome Medical is headquartered in South San Francisco​. ​To learn more, visit www.genomemedical.com ​and follow ​@GenomeMed.​

About the Partnership
Since our partnership in April 2020, LunaDNA members across the United States can access a network of clinical genomic specialists — including medical geneticists, genetic counselors, pharmacists, and primary care doctors — to better understand their health and DNA information.

Interested in learning more about your personal and genomic health? Get started here.

Is Eye Color Genetic?

Is Eye Color Genetic? | What Your Eye Color Has to Do With Your History

Eye colors are passed down through generations, but sometimes genetic variations can lead to surprising results in eye colors. Learn about the genetics of eye color in this guide.

Whether eyes are blue or brown, eye color is determined by genetic traits handed down to children from their parents. A parent’s genetic makeup determines the amount of pigment, or melanin, in the iris of the his or her child’s eye. With high levels of brown melanin, the eyes look brown. With minimal levels of the same brown melanin, the eyes look blue. However, a genetic variation can cause a child’s eye color to be unpredictable, resulting in two blue-eyed parents having a brown-eyed child.

Know Your Health: Genetics of Eye Color

Eye colors have evolved over time and have roots in our ancestry. Although eye color is determined by genetic makeup, variations can cause different shades to appear. Learn more about the genetics of eye color, including:

  • How is Eye Color Determined?
    • Is Eye Color Genetic?
    • Is Eye Color Inherited?
    • Can Eye Color Be Predicted?
  • What Does Your Eye Color Mean?
    • Brown Eyes
    • Blue Eyes
    • Green Eyes
    • Hazel Eyes
  • How Does Your Eye Health Impact Your Life?

How Is Eye Color Determined?

Genetic makeup determines the amount of melanin in the eye. In eye color, there isn’t blue or green pigment. All eye colors have the same brown melanin incapable of refracting light. The difference in eye colors is due to the concentration and location of the brown melanin on the two layers of the iris. People with brown eyes have melanin on the back layer of the iris and some on the front layer, which absorbs more light and causes the iris to look brown. Eyes with no melanin on the front layer of the iris scatter light so that more blue light reflects out, so that the eyes appear blue.

The chromosomes a child inherits carry genetic information that determines eye color. Differences in the copies received from each parent causes variations in the amount of melanin produced. A region on chromosome 15 has a big part in determining eye color. The OCA2 and HERC2 genes are located in this region.

The OCA2 gene (formerly called the P gene) provides instructions for producing the P protein located in the melanocytes (specialized cells that produce melanin). If more protein is produced, then the eyes received more melanin, and eye color leans toward the brown end of the color spectrum. When less protein is produced, the eyes receive less melanin and eye color leans toward the blue end of the spectrum. Although nearly 75 percent of eye color is controlled by the OCA2 gene, other genes provide a pathway for melanin. These genes can raise or lower melanin levels, causing a child to have more or less melanin than either parent. These variations can result in blue-eyed parents having a brown-eyed child, or brown-eyed parents having a blue-eyed child. The former is more likely than the latter.

Is Eye Color Genetic?

Each cell in the human body normally contains 23 pairs of chromosomes. Chromosome 15 likely contains 600 to 700 genes integral to producing proteins. Two of these genes, OCA2 and HERC2, play a significant role in eye color selection.

Although the OCA2 gene produces the protein responsible for melanin, the HERC2 gene controls the OCA2 gene by turning its protein production on and off. The presence of at least one genetic variation in the HERC2 gene can reduce the amount of melanin produced, leading to lighter eyes. Other genes working with OCA2 and HERC2 have a smaller role, but on rare occasions override OCA2 to determine eye color.

Is Eye Color Inherited?

Eye color was once thought to be the result of a single hereditary trait. It was thought that each person received one eye color gene from each parent, and the dominant gene determined eye color. In this model, the brown-eye color gene was always dominant over the blue-eye color gene, and only two blue-eye color genes could color eyes blue.

Charles and Gertrude Davenport developed the dominant brown eye model in 1907. They suggested that blue eyes were caused by a single recessive gene, and blue-eyed parents could never produce a brown-eyed child. Dominant and recessive genes refer to inheritance patterns, and describe how likely it is for a certain trait to pass from parent to offspring.

Today, we know this model is simplistic, and that many genes determine that eye color. Although we can predict the color of a child’s eyes based on the parent’s eye colors, other genetic factors may alter the outcome.

Can Eye Color Be Predicted?

While it is possible to predict the probability of eye color, genetic factors may alter the outcome. Movie star Elizabeth Taylor’s parents probably did not predict their daughter’s rare violet eyes. Taylor’s eye color is thought to be the result of a genetic mutation in the FOXC2 gene, which causes a specific amount of melanin that produced a striking eye color and may cause double eye lashes as well as heart problems.

With eye color controlled by more than one gene, it is possible for a newborn to inherit any eye color. Predicting eye color is further complicated because it sometimes changes after birth. A baby’s blue eyes can turn brown as more melanin is deposited into the iris over the first three years of life.

What Does Your Eye Color Mean?

According to one theory, almost everyone (99.5 percent) with blue eyes might be able to trace their ancestry back to the same blue-eyed ancestor that lived in the northwest part of the Black Sea region some 6,000 to 10,000 years ago. This is based on the DNA analysis of about 800 blue-eyed people, in which only one person did not have the same blue-eye genetic mutation as the rest of the group. This mutation seems to have occurred during the Neolithic period (or New Stone Age) during the great agricultural migration to the northern part of Europe. Nearly all blue-eyed humans have this same mutation in the same location in their DNA. By contrast, brown-eyed humans have more variation in their DNA when it comes to eye color.

Brown Eyes

The majority of people in the world have brown eyes. The color brown is a result of a high concentration of melanin in the iris causing more light to be absorbed and less light to be reflected. Because of this, brown eyes are more naturally protected from the sun. This likely had evolutionary benefits similar to darker skin being able to withstand the hot sun longer. The genes responsible for skin color are closely linked to those that cause eye color.

Though brown eyes are the most common genetic eye color, there is more genetic variation among those with brown eyes than those with blue eyes. This may account for the variations of brown eye colors. These variations come from different genes on different chromosomes that carry genetic eye color information from our ancestors.

Blue Eyes

Originally, all humans had brown eyes. Some 6,000 to 10,000 years ago, a genetic mutation affecting one gene turned off the ability to produce enough melanin to color eyes brown causing blue eyes. This mutation arose in the OCA2 gene, the main gene responsible for determining eye color. Since blue eyes have survived throughout many generations, researchers think there may have been some evolutionary benefit, though the exact reason is unknown.

Blue eyes are the result of low concentrations of brown melanin, not blue pigmentation. Less melanin allows more light to reflect back to wavelengths on the blue color spectrum, which in turn make eyes appear blue. The reason why eyes are blue is the same reason the sky is blue. Some 8 to 10 percent of humans worldwide have blue eyes.

Green Eyes

Only about 2 percent of the world’s population has green eyes. Green eyes are a genetic mutation that produces low levels of melanin, but more than blue eyes. As in blue eyes, there is no green pigment. Instead, because of the lack of melanin in the iris, more light scatters out, which make the eyes appear green. Changes in light make lighter eyes look like they are changing colors like a chameleon.

Hazel Eyes

Hazel eyes are sometimes mistaken for green or brown eyes. They are not as rare as green eyes, but are rarer than blue eyes. Only about 5 percent of the population worldwide has the hazel eye genetic mutation. After brown eyes, they have the most melanin. . The combination of having less melanin (as with green eyes) and a lot of melanin (like brown eyes) make this eye color unique.

The color combinations in shades of green, brown, and gold are endless with hazel eyes, depending on the concentration of melanin. The light scatters as it does with blue and green eyes.  As with blue and green eyes, hazel eyes may appear to shift colors depending on the light. The eye color doesn’t actually shift, perception does. It is unknown if hazel eyes developed from brown eyes or green.

How does your eye health impact your life?

Your eye health may significantly impact your everyday life, from socializing with friends to driving at night. Share your eye health experiences to help scientists better understand your eyes’ impact on your daily life. Get started here.