Prenatal and genetic tests raise some concerns at times. Some people believe they can be used to get bespoke children, with bold features. In reality, screening tests only serve to verify the health status of embryos and fetuses. Epigenetics proper is only science fiction, at least at the moment.
A study conducted by Dr. Shai Carmi of the University of Jerusalem confirms this. The study highlights how many traits depend on variants on multiple genes, not on a single mutation. This complicates prenatal screening, at least for certain diseases - and actually makes it impossible to program a child to taste. Traits such as intelligence or height depend on a large number of factors, some environmental and other genetic. Based on the knowledge we have today, trying to select an embryo based on future intelligence would be a titanic undertaking.
To test their point, the researchers used a computer-based simulation based on the genome of real people. Starting from these, they created 10 hypothetical embryos for each pair. The process imitated what happens during a true IVF cycle, with a limited number of embryos. After that, the researchers assigned a score to each embryo, based on the supposed genetic advantages.
The selected embryos should have been the parents' genetic creams. Still, the advantage over the others turned out to be quite small. The hypothetical adults would have had an IQ 3 points above the average of the unselected embryos. The same applies to the height. All at the price of genetic tests that are still not precise, at least when it comes to traits of the person and not genetic diseases.