Single allele lowers heart risk

Were it not for a single base pair insertion/deletion mutation in the MMP3 gene sequence, the incidence of heart disease among modern Europeans would be much higher, according to the authors of a study published this week in Current Biology. But others cast doubt on the suggestion that the gene necessarily played such an important role.

"Our analyses show how positive natural selection can shape variation in a human population, because we exclude other possibilities, said lead author Matt Rockman, of Duke University. "For a long time, it's been argued that genetic variation underlying disease is the result of deleterious mutations. That is, there's a 'good' version of the gene but occasionally a 'bad' mutation arises that leads to disease susceptibility."

"However, what we find in the case of MMP3, and what many researchers are finding in studies of other genes, is that the genetic variation underlying disease is often ...