Dear All, It might be useful for me to clarify why I proposed the CVS use case in the first place. I saw Sam's assertion that "the fetus can be treated as part fo the mother", and that bothered me because while that's the legal state of affairs in many places, if implemented thoroughly it also means every woman is a genetic mosaic with different genotypes every time she's pregnant, which seems like a minefield to me - do we really want to make it that hard?
The placenta arises because it would appear not to be part of the fetus, and it's the mother who develops it, but it's actually the thing which is tested to establish a genotype for the fetus wihtout being invasive of it (it replaced fetal blood sampling in the second trimester for that purpose), so again the mosaic problem arises. My main concern was to have a way of clearly determinig which genotype(s - some people are mosaics anyway!) are actually the mother's, which are the fetus' and which are neither in that like the placenta they simple vanish from the picture outside a given window... The bone marrow case was more about seeing a bone marrow transplanted patient as a therapeutically created mosaic, but making sure that it could be recorded that this individual has in effect an unreliable blood genotype for extrapolating that to other organs (antenatal care at least in the UK assumes that if you've sampled the blood you've sampled the individual...!). It's also interesting because the donor is almost certainly a close relative (so it's perhaps not the same kind of secret) but is also probably alive (ie the organ transplanted has not been "harvested" after a trauma...). Again it's a window, but this time open-ended assumig graft versus host can be avoided... I'm beginning to see a general question here, which would also cover prostheses (just because the hip is made of titanium...) but more interestingly tumours which are "of" the organ in or at which they are located, but which are histologically and genetically different, are additional masses, and may also be "temporary" in that once detected they may be removed or suppressed/shrunk in some other way... On the question of assigning identifiers, when the reason for the selective termination of one of twin pregnancies is a lab result and a prediction rather than something you could see visibly on ultrasound etc, does anyone know how obstetricians work out which the target fetus is? Normally in medicine such things seem to be done by laterality (for kidneys, limbs, etc.) but I was under the impression that fetuses were too mobile to reliably do it that way... Regardig new EHRs etc, might there be scope for mimicking what nature does - a child EHR which for example must inherit its identifier context from its mother as it really can only be identified meaningfully by a qualifier of "this is the demographic person inside which it is located"...? Yours, Matthew -- "Mr. Matthew Darlison BA MA" <M.Darlison at ucl.ac.uk> Senior Research Fellow, Clinical & Applied Bioinformatics UCL Centre for Health Informatics and Multiprofessional Education (CHIME) APoGI on the Web at http://www.chime.ucl.ac.uk/APoGI/ - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
