Clients at fertility clinics should be told if their sperm donor is gay in case their children end up gay too, says a Christchurch geneticist. Associate Professor Frank Sin of Canterbury University says that even though the existence of a single "gay gene" is yet to be proved, and no evidence exists to show that gay people are more likely to pass on this hypothetical gene, potential parents should nevertheless be warned. Sin told The Dominion Post that it was "not daydreaming" to suggest that sexual orientation could be inherited, and that people had the right to know the trait could be passed on. Genetics experts generally agree that there is a genetic component to sexual orientation, but the exact nature of this is yet to be determined, as is whether it is an inheritable trait. University of Canterbury geneticist Jack Heinemann feels that Sin has jumped the gun. "In my view, Sin's recommendation is an unjustified extrapolation from the science behind it," he told the Christchurch Press, adding that it was not clear why sexuality should be singled out as a trait to be notified. "Would you warn recipients of sperm that their baby might be a boy or a girl? What should be the criteria for notification, and who decides what they should be?" Allan-John Marsh of Wellington gay business group GAP says Sin's suggestion is insulting and pathetic. His sister, parents and uncles and aunts were "secure in their heterosexuality...It [the suggestion] implies that being gay is somehow inferior. It's not a disease, not a handicap, even taking the view that you are born this way. So be it." AIDS Foundation spokesman Steve Attwood questioned the need for sperm donor recipients to be notified about the donor's sexuality. "It sounds like a potential bogeyman parents need to be warned against. Playing with this sort of thing could signal a return to the time when being gay was regarded as a disease which needed to be treated to find a so-called cure," he said. John Hutton, medical director at the Fertility Associates clinic said that it would be irresponsible for their organisation to tell recipients that sexual orientation could be passed on, in the absence of any conclusive evidence of a gay gene. However, the clinic's national director Richard Fisher said that all donors are asked their sexual orientation, along with other extensive background information. All of this is passed onto potential recipients, who select the donor they deem most suitable.