Common disease variants are invariant

A recent article in The American Journal of Human Genetics by Lohmueller et al shows that SNP variants involved in 'common' diseases tend not to vary considerably between the two populations they compared.

This is good news in the world of gene hunting since it suggests that these variants arose prior to the divergence of human populations, and that they variants are therefore common to most human populations. This is not to say that genetic heterogeneity does not exist, since there are likely to be other mutations that influence disease that are population specific, but it is encouraging since it means that it should be reasonably easy to replicate associations with some of the common variants (indeed that was one of the criteria for selection used in the paper).