Researchers from The Chinese University of Hong Kong have found a way to map the entire genome of a fetus based on the genetic material from a blood sample that is taken from the mother. This new discovery might lead to a non-invasive way to do prenatal screening for genetically heritable disorders. A report about their research was published in “Science Translational Medicine”. More work will need to be done with this new technique before it will be ready to be used to replace amniocentesis.
This new technique involves taking a close look at the “floating” fetal DNA that is present in the blood of a pregnant woman. It has been used before to help detect genetic and chromosomal problems that a fetus might have. In the past, however, the focus has been on finding out about just one specific disease. This new technique, however, allowed researchers to sequence nearly four billion DNA molecules. They were then able to look for specific genetic variations and mutations in the genome of the fetus.
Currently, prenatal diagnosis of genetic disorders involves amniocentesis. This procedure involves removing a very small amount of amniotic fluid from the sac that surrounds the fetus. To remove it, a needle is inserted into the uterus, through mother's abdomen. The fluid is then sent to a lab, and tested for genetic disorders. Amniocentesis, (like other invasive prenatal medical procedures), has a 1% risk of causing a miscarriage to happen. This percentage may sound low, until you realize that your baby could be in that 1%.
This discovery of a new way to do genetic screening from the mother's blood sample is incredibly important for many reasons. This procedure doesn't come with the risk of miscarriage. It can provide information about the entire genome of the fetus, which is more than the invasive procedures are able to do. The new procedure could help detect the presence of cystic fibrosis, Down's Syndrome, and sickle cell anaemia seven weeks earlier than existing methods of prenatal screening can.