The God gene

A new book is causing waves by claiming that some people have a genetic predisposition towards spirituality/'self-transcendence':

Dr Dean Hamer, the director of the Gene Structure and Regulation Unit at the National Cancer Institute in America, asked volunteers 226 questions in order to determine how spiritually connected they felt to the universe. The higher their score, the greater a person's ability to believe in a greater spiritual force and, Dr Hamer found, the more likely they were to share the gene, VMAT2.
Studies on twins showed that those with this gene, a vesicular monoamine transporter that regulates the flow of mood-altering chemicals in the brain, were more likely to develop a spiritual belief.
Growing up in a religious environment was said to have little effect on belief. Dr Hamer, who in 1993 claimed to have identified a DNA sequence linked to male homosexuality, said the existence of the "god gene" explained why some people had more aptitude for spirituality than others.
"This is not a thing that is strictly handed down from parents to children" [he said.] "It could skip a generation - it's like intelligence."

From what I've read, Hamer's scientific claims are still far from being scientifically substantiated -- and clearly, merely having a 'God gene' would not mean that someone had no choice but to end up religious, or vice versa. Still, the very concept raises some interesting questions. Would the existance of a 'God gene' result in religious people becoming be more accepted in a secular society -- or atheists (who presumably lack the gene) becoming be more accepted in religious societies? Would parents one day be able to genetically engineer their children to make them more or less spiritually inclined? And -- most importantly -- would proof that faith is influenced by genetics undermine or reinforce the notion of religion? I'd be interested to hear people's opinions on the latter question...