Can two blue-eyed parents give birth to a brown-eyed child?

Kevster wrote:

Genetics rocks! In humans, brown eyes ARE dominant over blue eyes. ...

It has been shown that it CAN happen however and the case that was decsribed in Shib's post could be explained by a mutation of a gene I guess.

Shib wrote:

Eye color is an inherited trait influenced by more than one gene.

The genetic basis for eye color is actually far more complex. At the present, three gene pairs controlling human eye color are known. Two of the gene pairs occur on chromosome pair 15 and one occurs on chromosome pair 19. The bey 2 gene, on chromosome 15, has a brown and a blue allele. A second gene, located on chromosome 19 (the gey gene) has a blue and a green allele. A third gene, bey 1, located on chromosome 15, is a central brown eye color gene.

Geneticists have designed a model using the bey 2 and gey gene pairs that explains the inheritance of blue, green and brown eyes. In this model the bey 2 gene has a brown and a blue allele. The brown allele is always dominant over the blue allele so even if a person is heterozygous (one brown and one blue allele) for the bey 2 gene on chromosome 15 the brown allele will be expressed. The gey gene also has two alleles, one green and one blue. The green allele is dominant to the blue allele on either chromosome but is recessive to the brown allele on chromosome 15. This means that there is a dominance order among the two gene pairs. If a person has a brown allele on chromosome 15 and all other alleles are blue or green the person will have brown eyes. If there is a green allele on chromosome 19 and the rest of the alleles are blue, eye color will be green. Blue eyes will occur only if all four alleles are for blue eyes. This model explains the inheritance of blue, brown and green eyes but cannot account for gray, hazel or multiple shades of brown, blue, green and gray eyes. It cannot explain how two blue-eyed parents can produce a brown-eyed child or how eye color can change over time. This suggests that there are other genes, yet to be discovered, that determine eye color or that modify the expression of the known eye color genes.

How does a gene, a section of a chromosome in the cell nucleus, make my eyes a particular color?

The exact color of the human eye is determined by the amount of a single pigment called melanin that is present in the iris of the eye. Melanin is a dark brown pigment that is deposited on the front surface of the iris. If a lot of melanin is present, the eye will appear brown or even black. If very little melanin is present the iris appears blue. Intermediate amounts of melanin produces gray, green, hazel or varying shades of brown. Genes work by directing the production of enzymes, chemicals that control all of the processes that occur in our body. Eye color genes, through the enzymes they produce, direct the amount and placement of melanin in the iris. In general Caucasian babies are born with blue eyes because at the time of birth they haven't begun to produce melanin in their irises. Their eyes may change to green, brown or other colors as melanin production begins. Babies of other ethnic origins such as African, Asian, Hispanic and Native American, are often born with brown or black eyes. Albinos have no pigment in their irises so the blood vessels in the back of the eye reflect light making the eyes look pink. Albinos also lack melanin in their skin and hair. Since albinism is caused by a recessive allele, two normal parents may produce an albino. An albino can have normal offspring if the other parent is normal for melanin production.

Victor wrote:

I thought its was more new mothers in their forties than in their teens.