Is it possible for two brown eyed parents to have a blue eyed baby?
Two brown-eyed parents (if both are heterozygous) can have a blue-eyed baby. However, since eye color is polygenic, several other genes exert their effects as well. So yes, while it's unusual, it is possible for blue-eyed parents to have a brown-eyed child!
If both of you have brown eyes, then there is generally a 25% chance that the baby will have blue eyes if both of you carry the recessive blue-eye gene. But if only one of you has a recessive blue-eye gene, and the other has two brown, dominant genes, then there is a less than 1% chance of the baby having blue eyes.
- First of all, it's definitely not true that all babies are born with blue eyes. Babies of African American, Hispanic and Asian descent are usually always born with dark eyes that stay that way. This is because these non-white ethnicities naturally have more pigment in their skin, hair, and eyes.
- Each human has two genes for eye color - one Brown/Blue and one Green/Hazel. Brown is dominant over all other alleles. Green and hazel have incomplete dominance. The heterozygous allele combination Gg produces hazel eyes.
- But there is one key risk factor for Down syndrome: maternal age. A 25-year-old woman has a 1 in 1,200 chance of having a baby with Down syndrome; by 35, the risk has increased to 1 in 350; by age 40, to 1 in 100; and by 49, it's 1 in 10, according to the National Down Syndrome Society.
Updated: 27th September 2018