by admin
When preparing for childbirth, most parentsbegin to wonder what eye color their child will have. If you and your partner both have the sameeye color, it’s likely your child will have the same, but this iscertainly not always the case. A child’seye color is determined by the genetics both you and your partner have and cancombine in many ways to produce interesting results.
Changes
Of course, it’s important to note that eye coloralso changes over time. Most babies areborn with blue eyes, but three months down the road they could turn any numberof colors. This is due to melaninproduction. It is common for babies tohave a lack of melanin when they’re born, causing them to have blueeyes. Over some time after the baby isborn, light will stimulate the creation of melanin and their eye color willlikely change. Of course, there’s nosure way to know until the baby is born, but there are some ways to determinewhat eye colors are dominant and the likelihood of them passing down to yourchild.
How does it work?
Babies inherit equal eye color genetics from both parents — 50% from each. From here, genes mutate to produce what arecalled alleles. Alleles are alternativeforms of a gene that, in this case, are responsible for giving your baby acertain eye color. The allele genes comein the form of brown, blue, or green, with brown being dominant, followed bygreen, and blue being the least dominant or what is called recessive.
Given this information, you can determine what eye colorsare dominant in the parents. There aremany combinations involving dominant and recessive alleles, but you can build achart to help you understand the possible combinations your child couldhave. For example, if both parents havethe dominant brown allele, it is likely your child will have brown eyes and thesame if one parent has a dominant brown allele and the other a recessive blueallele.
Brown and green alleles will always out-rule blue alleles,with brown being the most dominant.
Blue will always be recessive. If both parents have a blue allele, it islikely that the child will have blue eyes.However, if one parent has green eyes and the other blue, your childwill most likely have green eyes, as green is dominant over blue.
Combinations
Let’s take this back to scienceclass. As mentioned earlier, every humanhas two copies of genes, deriving from both the mother and father. When two copies are dominant it’scalled hom*ozygous, which we can label as “BB”. Conversely, when two copies are recessive, it’slabeled as “bb”, or heterozygous.When finding out what eye colors are dominant between you and yourpartner, it’s important to keep in mind the fact that combinations ofthese genes exist and could affect your child’s eye color. For example, when someone has brown eyes, itdoesn’tnecessarily mean they have hom*ozygous genes. It’s possible for them tohave a combination, or “Bb”, having one dominantbrown allele and one recessive blue allele.In this case, because brown is dominant over blue, they will have browneyes.
Below is a chart that shows an example of how you coulddetermine your child’s eye color, given you know exactly what gene combinationthe mother and father possess. In thisexample, we will say the mother has brown eyes, but carries a recessive blueallele from her father. The father inthis example has blue eyes and carries both recessive alleles. The white boxes indicate the combinations ofthese alleles that your child could have.
| B | b | |
| b | Bb | bb |
| b | Bb | bb |
As you can see in this example, your child has a 50/50chance of getting brown (Bb) or blue eyes (bb).If the mother had a dominant hom*ozygous genotype (BB), all of your child’scombinations would read “Bb”, meaning they wouldlikely have brown eyes.
Things start to get a little complicated if you don’tknow exactly what eye colors are dominant in your family lineage, but most ofthe time you can determine the probability pretty easily by understanding thedominance order: Brown, followed by green, and, last but not least, recessiveblue.
At Advanced EyeMedical we are happy to answer any of your eye-centric inquiries. If you’d like to know more about our eyeprocedures, feel free to visit our website or contact us at866-997-2020 for a free consultation.
