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The hard part is figuring out the maternally inherited foetal DNA, because it's already present in the mother's bloodstream. For features which are present in
by Estragon 16y ago
The hard part is figuring out the maternally inherited foetal DNA, because it's already present in the mother's bloodstream. For features which are present in the mother but not the father, it's fairly easy with the data they have. For vice versa, it's probably not going to be possible for some time.
- carbocation 16y agoAgreed, mostly, at least from first principles. The enrichment will be very modest. On average for any given chromosome, 45% of DNA in the mother's blood should be maternal DNA from one chromosomal copy or the other. This gets us to 90%. The remaining 10% is split between one paternal copy and one maternal copy. This means that--if we ignore other differences such as fragment length--you're potentially trying to label the chromosomal copy that comprises 50% of DNA as the one inherited by the fetus, versus the one comprising 45% of DNA as the one not inherited by the fetus. That's a very small enrichment. Now, because of the length differences that they identified, they may be able to vastly enrich for fetal DNA (or precipitate out maternal DNA), obviating this problem.