Eye color is an inherited trait influenced by more than one gene.Certainly the model learned in school about brown-eye color being dominant over blue falls is an over-simplification. Indeed the one-gene theory is not valid; there is no single gene for eye color. There are two major genes and other minor ones that account for the tremendous variation of human eye color.In humans, three loci associated with eye color are currently known: EYCL1, EYCL2, and EYCL3.These genes account for three phenotypic eye colors (brown, green, and blue) in humans.Eye color is demanding, as all four genes must determine the same color for the eye color to be pure; otherwise a mixed color such as hazel will result.Eye color usually stabilizes when an infant is around 6 months old.
In 2006, the molecular basis of the EYCL3 locus was resolved.In a study of 3839 people, researchers reported that 74% of total variation in eye color was explained by a number of single nucleotide polymorphisms (SNPs) near the OCA2 gene (OMIM: 203200). OCA2 was previously known because, when mutated, the gene can result in a type of albinism. The recent study showed that different SNPs strongly associate with blue and green eyes as well as variations in freckling, mole counts, hair and skin tone. The authors speculate that the SNPs may be in an OCA2 regulatory sequence and thus influence the expression of the gene product, which in turn affects pigmentation.
So it is possible.
· 1 decade ago