Parents may soon be able to find out if their unborn child is prone to any inherited diseases, researchers said on Thursday, after developing a non-invasive technique to draw the entire gene map of the human foetus. By analysing a sample of the mother’s blood, which contains DNA from the foetus, scientists in Hong Kong and the United States were able to identify all the DNA strands that belong to the child and piece them together. “Before this work, people only could look for one disease at one time but now you can construct a screen for a number of diseases which are prevalent in any particular population,” said lead author Dennis Lo, professor of medicine from the Chinese University in Hong Kong.
The research team’s breakthrough was discovering that the mother’s plasma holds the entire foetal genome. Previously, only part of the baby’s DNA was thought to be in the mother’s blood. “Now that we know (the) entire foetal genome is in there, you can look for any disease that is genetically inherited.”
The study, published in the journal Science Translational Medicine on Thursday, recruited a couple undergoing prenatal diagnosis for a hereditary blood disorder, beta-thalassemia. “In the mother’s blood, 90 per cent of the DNA is her own ... and 10 per cent is the baby’s. Half of the foetal genome is from father and half from mother,” Lo said.