باروری و ناباروری ایران

By Clare Wilson

THE prospect of creating intelligent designer babies has been the subject of ethical debate for decades, but we have lacked the ability to actually do it. That may now change, thanks to a new method of testing an embryo’s genes that could soon be available in some IVF clinics in the US, New Scientist can reveal.

The firm Genomic Prediction says it has developed genetic screening tests that can assess complex traits, such as the risk of some diseases and low intelligence, in IVF embryos. The tests haven’t been used yet, but the firm began talks last month with several IVF clinics to provide them to customers.

For intelligence, Genomic Prediction says that it will only offer the option of screening out embryos deemed likely to have “mental disability”. However, the same approach could in future be used to identify embryos with genes that make them more likely to have a high IQ. “I think people are going to demand that. If we don’t do it, some other company will,” says the firm’s co-founder Stephen Hsu.

For many years, it has been possible to do simpler genetic tests on embryos as part of IVF. For example, parents at risk of having a child with cystic fibrosis have the option to undergo IVF and select an embryo that doesn’t carry the gene behind the condition. It is also possible to screen for several other conditions caused by a single gene, as well as those caused by chromosomal abnormalities, such as Down’s syndrome.

However, most medical conditions are influenced by hundreds of genes, which has made it impossible to screen out embryos with a high risk of heart disease, for example, or select embryos with a low likelihood of experiencing depression. This is true for traits like intelligence too.

In recent years, it has become possible to work out a person’s likelihood for having certain conditions or traits by analysing many DNA regions at once to calculate something called a polygenic risk score (see “Predicting an embryo’s future traits“).