Expert: Dana Krempels, Ph.D. - 8/28/2007

Question
I am 4 mo. pregnant and I have a question about what my baby's eye color might be. I have med/dark brown eyes and my husband has blue, here is a chart of family members eye colors:
He has blue,his parents both have blue eyes, all four sets of grandparents have blue eyes.
I have dark brown eyes, my mother has light hazel, my father dark brown,
my grandparents have: 1 has blue, 1 has light hazel, 2 have dark brown.
I think brown is usually dominate but my brother has 2 children with blue eyes and two with brown ( his wife also has blue eyes) so I know that I carry the recessive blue eye gene. what are the chances of this baby having blue eyes? this is all for fun and as long as the baby is healthy I don't care, but thought it might be fun to see what the predictions might be...

Answer
Dear Kimberly,

Since your mother has hazel eyes, you have inherited the recessive "light eye" allele from her, though in your mother's case the blue eyes are modified by overlying yellow pigments (carotenoids) that make the eye look hazel/green.

If the father has blue eyes, this means that the genetics of the cross (relative to the eye color allele) are:

Bb (you) x bb (father)

Creating a matrix of all possibilities, this means there is a 50% chance the baby will have dark brown eyes (Bb), and carry the blue eye gene s/he got from dad and a 50% chance that s/he will inherit b from both you and dad, making him/her have blue base color.

However, since eye color is controlled by more than one gene, the baby also could inherit the carotenoid depositing pigments that could make those blue eyes green or hazel.  You'll just have to wait and see.  :)

Hope everything goes well, and that the baby's eyes are beautiful as the rest of him/her, no matter what color.

Take care,

Dana