Ever wonder how you got the eye color you did or why you have a different eye color than the rest of your family. Don’t worry, it doesn’t mean you are adopted. The genetics of eye color are a lot more complicated than the Punnet squares you did in Biology 101 might suggest. After speaking to our favorite Atlanta eye doctor, we were able to put together this great post on the genetics of eye color.
Eye color is determined by the different amounts of pigment that is present in the iris. How much pigment and the pattern that it is distributed in is determined by your DNA and determines what your eyes will look like.
Babies inherit a chromosome from each of their parents. One part of DNA on a chromosome is what is known as a gene. As you probably already know genes are the most basic unit when it comes to heredity. They determine everything from our eye color, height, susceptibility to disease to things as trivial as the shape of our fingernails. What you might not know though is that there is something called alleles which are variants of a specific gene and determine the whether or not a specific characteristic appears.
So, for any inherited trait there are two alleles. However, there are dominant alleles meaning that one allele can override the other. The allele which isn’t apparent is called recessive.
That all sounds very technical but what it boils down to is this. If you have a brown allele and a blue allele, then the brown would be the dominant one in the pair. So, you would have brown eyes even though you have a blue allele. That sounds simple, right?
However, there isn’t just one pair of genes that universally control a single trait. Right now, we know of three gene pairs that determine a person’s eye color.These genes are the EYCL1 (gey), the Green & Blue eye color gene which is located on chromosome 19. The second is the EYCL2 (bey1), which is the central brown eye color gene, which is thought to be located on chromosome 15. EYCL3 (bey2), the Brown & Blue eye color gene which is also located on chromosome 15.
What about more unusual colors, how are they determined? Other eye colors like black, grey, and hazel are not yet explained. Scientist aren’t yet sire how those eye colors are produced. Meaning that eye color is still an evolving area of research and has yet to be fully understood.
To learn more about eye colors and see what the probability of a certain eye color, check out this eye color calculator from Baby Center.
Otherwise, you can schedule an appointment with your local Atlanta or Woodstock eye doctor to learn more.