Blue eyes

A nice study in Hum Genet by Eiberg hit the public press (and the blogosphere 1|2). Although I agree with most commentators that this is a sound study with a bit antiquity dust in the methods, I am unsure if I should believe the main conclusion of a founder mutationat the Northern part of the Black Sea Region or any positive selection related to vitamin D. My first problem comes with the trait: Has the following eye a rs12913832 GG genotype or not? Coloring is certainly age dependent while this has not been taken into account.
The family data otherwise are convincing (except that I do not understand a base “q” at the h-2 haplotype) while the functional data are less clear without examining melanocyte expression.
I agree on the fact that the 28 species depicted currently in the Genome Browser have an “A” and brown eye color as default but I am hesitating to accept any founder mutation wheresoever without a detailed work up of the population history. Probably not know to Eiberg et al. , the ALFRED database has some allele counts. To make my argument simple: With 68% of Italians in Bergamo having a “G” (q=0.68), I would expect q^2 or 46% of Italians on the street having blue eyes. So it will take some more research before we can put this into the textbooks. Unfortunately the new discovery is not be very helpful in forensics as the phenotypic outcome is so much related as FIG 1A and FIG 1B in the original paper.


  1. But most carriers will be heterozygotic and thus brown-eyed. And there is also the possible link with introversion that would make them fewer on the streets.

Comments are closed.