Factor V Leiden -- An Unselfish Gene?

Nearly two decades ago, Richard Dawkins proposed the concept that genes possess an inherent property of “selfish replication.”1 He argued, anthropomorphically, that these basic units of heredity behave in a manner that guarantees their self-perpetuation. However, a flawed gene would be eliminated from the species by selective pressure against the expression of a deleterious trait. Thus, only the most robust genes would be transmitted to subsequent generations. In this issue of the Journal, Greengard and her colleagues2 describe a homozygous mutation in the gene for coagulation factor V that seems to have no adverse clinical effects. Their report suggests that . . .