Nearsightedness

A DNA test may be able to explain why you are nearsighted and predict whether you have a genetic tendency to need glasses. Nearsightedness may be genetically coded in your DNA, but it may also be the result of environmental factors.

Were you predestined to wear contacts or glasses? Is it becoming more difficult for you to see things that are far away? Are you concerned about a recent eye exam that didn’turn out favorably? Nearsightedness, also known as myopia, is a condition that may actually be a result of your genetic makeup. With DNA testing, it is now possible to find out if genetics has influenced your nearsightedness.

In people with normal sight, the eye focuses images onto the retina, which is the light-sensitive area at the back of the eye. Nearsightedness is the result of a “refractive error“, which means the image is focused in front of the retina instead of onto it. With nearsightedness, distant objects appear blurry while objects nearer to the eye are in focus.

Scientists and researchers have discovered three genetic variants that can make you more susceptible to nearsightedness. However, it is important to keep in mind that not all nearsighted people possess the gene variants and not everyone with the variants is nearsighted. Nearsightedness can also be caused by environmental factors such as education, urban living, outdoor activities and doing work that requires your eyes to focus on something close-up for long periods of time.

If you want to find out if you have it in your genes to be nearsighted, take the Nearsightedness (Myopia) DNA Test today!

Genetics 101

Every cell in the human body contains DNA– a long complex chain made of billions of bases called nucleotides. Only four types of nucleotides compose the DNA chain: These are A=Adenine G = Guanin, T=Thymine, C= Cytosine. The DNA chain is packed in 23 separate packages called chromosomes, which make our genome. A gene is a sequence of hundreds, thousands or even tens of thousands of nucleotides. Human cells have two copies for almost every gene in our genome. Together, all of our genes determine our physical characteristics and traits.

Nucleotide sequence in the DNA chain has some differences for each person, which is what makes each of us unique. A change in the sequence of even a single nucleotide can determine a person’s certain tendency. Studies have found that is it enough for a person to have a change in a single nucleotide (known as SNP-Single Nucleotide Polymorphism) to mark a gene and to be able to predict with certainty that this person has a specific tendency.
(read more about DNA and genes in Genetics 101).

Short Sightedness Test

Two, recent well-conducted genetic studies tested the DNA of over 25,000 people from across Europe. Published separately, the two studies were using a genome-wide association studies. This type of study involves the analysis of genetic sequences of individuals with and without a particular condition, in this case myopia, commonly known as short-sightedness. This allows researchers to compare their DNA and identify genetic variations that are more common in people with the condition.

Normally, the eye focuses the viewed image onto the retina, the light-sensitive area at the back of the eye. In myopia, there is a “refractive error” where the image is focused in front of the retina instead of onto it. This causes distant objects to appear blurred, while those nearer to the eye are clearer.

The results point to the fact that short-sighted people were more likely to possess up to three particular genetic variants, which the researchers say make a small contribution to the chances of having the condition.

The presence of the genetic variants may make people more susceptible to short-sightedness, but not all short-sighted people possess the gene variants and not everyone with the variants is short-sighted. Environmental factors such as education, urban living, outdoor activity and carrying out close-up work may also play a role, as may further variants still waiting to be discovered.

A tendency for short-sightedness is affected by certain modifications in the RASGRF1 gene (marker rs8027411 ).

These testimonials are based on fictional accounts, but for most of us, they are all-too familiar situations.

“My sister and I had a bet to see if we were predestined to be short-sighted as we both wear glasses. It was so interesting to see the results of the Short Sightedness Test. It turns out it’s in her DNA, but not in mine!”

“I’ve worn contacts since I was 15 and glasses since the age of eight-years old. It was so interesting to learn from the Short Sightedness Test that my short-sightedness was in my DNA! I never even thought to research into it before, but I’m really glad I did.”