The diagnosis for baby's genetic mutation has improved.
The researchers succeeded to detect the Down's syndrome using the mother blood and father saliva.
It is well-known that non cellular DNA is floating into the pregnant women's blood.
Previously, the floating cells are used to test the genetic mutation for the fetus.
However, the fetus DNA is very similar to the mother's DNA, so this accuracy was very low.
Especially, the accuracy against the boy is comparatively high because we can detect the Y chromosome in this cell.
However, this technology is used the genome sequence derived from mother blood/father saliva and compared to the reference.
I'm interested in using the floating cell-free DNA in blood.
Most important things are low invasive diagnosis.
If we can detect the mutation without hurting the mother and the fetus body, we could lower the lethal risk of both.
Genome of 18-week-old foetus deciphered
A blood sample from mum and saliva from dad have been used to sequence the genome of a foetus in the womb, by US researchers.
At the time, the mother was just 18 weeks into the pregnancy.
The doctors said the findings, reported in Science Translational Medicine, could eventually lead to foetuses being screened for thousands of genetic disorders in a single and safe test.
However, they also caution it would raise "many ethical questions".
The scientists at the University of Washington used pieces of the foetus' DNA which naturally float around in the pregnant woman's blood.
These fragments were then pieced together using the parents' DNA as a guide to build a complete 'map' of the foetus's genome.
They then compared the genetic map drawn 18 weeks into pregnancy with the foetus' actual DNA taken from the umbilical cord after birth. It was 98% accurate.
Genome of 18-week-old foetus deciphered - BBC News
The original article is here.
Noninvasive Whole-Genome Sequencing of a Human Fetus
Noninvasive Whole-Genome Sequencing of a Human Fetus | Science Translational Medicine
AbstractAnalysis of cell-free fetal DNA in maternal plasma holds promise for the development of noninvasive prenatal genetic diagnostics. Previous studies have been restricted to detection of fetal trisomies, to specific paternally inherited mutations, or to genotyping common polymorphisms using material obtained invasively, for example, through chorionic villus sampling. Here, we combine genome sequencing of two parents, genome-wide maternal haplotyping, and deep sequencing of maternal plasma DNA to noninvasively determine the genome sequence of a human fetus at 18.5 weeks of gestation. Inheritance was predicted at 2.8 × 106 parental heterozygous sites with 98.1% accuracy. Furthermore, 39 of 44 de novo point mutations in the fetal genome were detected, albeit with limited specificity. Subsampling these data and analyzing a second family trio by the same approach indicate that parental haplotype blocks of ~300 kilo–base pairs combined with shallow sequencing of maternal plasma DNA is sufficient to substantially determine the inherited complement of a fetal genome. However, ultradeep sequencing of maternal plasma DNA is necessary for the practical detection of fetal de novo mutations genome-wide. Although technical and analytical challenges remain, we anticipate that noninvasive analysis of inherited variation and de novo mutations in fetal genomes will facilitate prenatal diagnosis of both recessive and dominant Mendelian disorders.
