A team from the Beijing Genomics Institute in China has sequenced the genome of two foetuses in utero, in an attempt to detect their genetic risk for a certain number of diseases. To do this, they collected blood samples from pregnant women in which foetal cells were circulating. Once these cells were isolated, sequencing was carried out. The results have been published in Prenatal Diagnosis. One of the foetuses "presented genetic variants related to intestinal cancer, intestinal disorders and liver diseases" whilst the other foetus "had a gene variant associated with salt imbalance".
The Chinese team presents the technique as an "improved version" of screening carried out with the parents' genome and used to "establish the full genetic portrait of the developing foetus", but this has proved both "complicated and costly". The scientists also emphasised the fact that their "new" technique can be used "from the first trimester of pregnancy".
The information obtained with this prenatal test is of limited significance: "The impact of a gene variant on the risk of developing a disease throughout a person's life in fact varies depending on several factors including environment and lifestyle. The discovery of certain genetic variants in a foetus that has not yet been exposed to the world could ultimately prove nothing more than a slight health risk". Once conveyed to parents, these results could have dramatic consequences and lead to abortions.
Science post, Brice Louvet (13/02/2018)