Most Asian people have dark colored eyes, but occasionally you can see a blue eyed Asian baby. Before wondering if that Asian baby with blue eyes is actually the descendant of Caucasian parents, keep in mind that recessive genes are present in all parts of the globe and yes, Asians can have naturally blue eyes (and green, for that matter). However, it is very rare that somebody without Scandinavian ancestors somewhere on their bloodline has blue eyes (though still possible, as mutations happen everywhere).
Let’s start by making it clear that Asia has an enormous diversity in terms of ethnicities, and some of them (particularly some Mongolian ethnicities in Central Asia) has a lot of light haired and blue eyed people. In those groups, seeing an Asian blue eyed child (however striking the photography is) is pretty common. So a questions such as can Asian have blue eyes is a bit of a misnomer, as it groups too many very different ancestries to actually be easy to answer. However, the question could be easily rephrased to “Can a family with mostly brown eyes have a blue or green eyed baby?” The answer is: Yes, but rarely.
Recessive Genes and Why Your Baby Could Have Blue Eyes
Table Of Contents
Each human being has two copies of each gene, one coming from mum and another from dad (except for genes that are unique to the X chromosome, in which case boys will only inherit one copy of them from mum). However, only one of those copies will actually be expressed and affect how the baby looks like, or other things such as whether the baby is a leftie or has perfect vision. Most traits are affected by several genes, which makes the entire issue even more interesting.
Let’s go back to what needs to happen for a baby to have blue eyes. There are several genes controlling eye color in humans, but two of them are the most well understood ones. We can use them on our genetic baby eye color predictor to estimate the chances of a baby having blue, green or brown eyes, based on the eye color displayed by their parents. However, having brown eyes doesn’t mean that you only have the gene alleles for brown eyes. You could have a dominant brown eye allele, and a recessive green or blue eye allele that is just not expressed. If you have a child you have a 50% chance to pass that inactive or recessive gene to your baby, and that means a brown eyed couple can perfectly have a blue eyed baby, provided some ancestors on both sides of the family had the gene for blue eyes.
If we ignore the gene for green eyes, the chances of two parents having a blue eyed baby even if both of them have brown eyes is about 25%. Another 50% of their children will be carriers for the blue eye gene, even if they have brown eyes. And just 25% of their children will lose the blue eye allele completely. However, entire generations could be just carriers of the blue eye gene and express brown eyes, since that 25% chance is calculated individually for each new member of the family, it is not accumulative. In the case of an Asian family, a great-great-great grandparent could have been of Caucasian origin, and eventually result on a blue eyed baby.
Other Reasons Why You Can Be Asian With Blue Eyes
There are several other ways in which Asian blue eye color happens. For example, one of the most common ones would be albinism. Albinism is a genetic deficiency of melanin pigment production, which can be as low as 1% of normal. Ocular albinism affects exclusively the eyes, and could lead to a person with dark hair and skin but blue or light brown eyes.
Many forms of albinism are autosomal recessive which means people in a family may be carriers but not have somebody with albinism on their close family. Albinism is relatively common, and about 1 out of 70 people in the world are carriers, though ocular albinism type 1 and 2 are X-linked and as such affect predominantly males.
Can Blue Eyed People Have a Brown Eyed Baby?
In theory, blue eyes are recessive and you would need two copies of the recessive allele to have blue eyes. Which leads to the question: how can a baby with brown eyes be born from two blue eyed people? There are several ways in which this can happen.
The BEY2 or OCA2 gene is the responsible for making pigment that gives people brown eyes. If BEY2 is not working (recessive b allele) no pigment is made, and you have blue eyes. Blue eyes are blue because the back of the eye is slightly visible through a less opaque iris.
However, sometimes a gene can shut off another gene, so even if you have an active BEY2 gene you may express blue eyes (or light colored eyes in general, as this also applies to hazel and green eyes). So if somebody has a gene that shuts off the BEY2 gene, they will have blue eyes but a dominant BEY2 allele genotype. So while they look like they are bb they are actually Bb with a deactivated B gene due to a third gene, which we’ll call D. If that third gene is recessive, there is a chance that a baby will inherit the B allele and the d recessive version of the gene that deactivates the brown eye BEY2 gene. And that baby would have brown eyes, and be a carrier for both blue eyes and the recessive d gene that deactivates BEY2.