By Paul Rincon
A service that digitally weaves together the DNA of prospective parents to check for potential disease in thousands of "virtual babies" is set to launch in the US by December.
New York start-up Genepeeks will initially focus on donor sperm, simulating before pregnancy how the genetic sequence of a female client might combine with those of different males.
Donors that more often produce "digital children" with a higher risk of inherited disorders will be filtered out, leaving those who are better genetic matches.
Everything happens in a computer, but experts have raised ethical questions.
"We are just in the business right now of giving prospective mothers, who are using donor sperm to conceive, a filtered catalogue of donors based on their own underlying genetic profile," Genepeeks co-founder Anne Morriss told BBC News.
"We are filtering out the donor matches with an elevated risk of rare recessive paediatric conditions." ...
She was motivated in part by her own experience of starting a family. Her son was conceived with a sperm donor who happened to share with Morriss the gene for an inherited disorder called MCADD.
MCADD (medium-chain acyl-CoA dehydrogenase deficiency) prevents those affected from converting fats to sugar. It can be fatal if it is not diagnosed early.
Luckily, in Ms Morriss's case, the condition was picked up in newborn screening tests.
"My son has a pretty normal life," Ms Morriss said, "but about 30% of children with rare genetic diseases don't make it past the age of five."
Genepeeks has formalised a partnership with a sperm bank - the Manhattan Cryobank - and has a patent pending on the DNA screening technology. ...
Ms Morriss's business partner, Prof Lee Silver, a geneticist and expert on bioethics at Princeton University, New Jersey, told BBC News: "We get the DNA sequence from two prospective parents. We simulate the process of reproduction, forming virtual sperm and virtual eggs. We put them together to form a hypothetical child genome.
Lee Silver, another blast from the past. The Human Genome Project came with a rider mandating 5% of the money be spent on ethics experts. Thus, Lee Silver was omnipresent in the media back around 2000.
"Then we can look at that hypothetical genome and - with all the tools of modern genetics - determine the risk that the genome will result in a child with disease.
We're looking directly for disease and not carrier status. For each pair of people that we're going to analyse, we make 10,000 hypothetical children."
The process will be run for the client and each potential donor one by one, scanning for some 600 known single-gene recessive conditions. In this way, the highest-risk pairings can be filtered out.
If you are going to spend money for donor sperm, why not?
I could imagine a scenario — feel free to use this in a Lifetime movie — in which a woman is choosing between Donor X and Donor Y, and Genepeeks says Donor Y is clean but Donor X has a 1 out of 1000 chance of horrible Disease Z. But the lady says, But, from their pictures, I like X's smile more than Y's, so I'll go with Donor X. But then the baby is born with Disease Z, for which the mother can't forgive herself. Until, she discovers that ... well, I don't know what the plot twist would be because I lose interest in making up my own narratives with consistent rapidity.
But the subject of babymaking is inherently interesting.