I wonder what would happen if...

[BigRedBeta]

Originally Posted by cheerfulgreek

So do you think the body would just reject it? That's what I was thinking.

It's not that the mother's body rejects it, it's that the having either extra information (an extra chromosome hanging out) or missing information (having only one chromosome when you should have two) results in a non-viable fetus. This would be due to having too much or too little of needed protein or some other form of imbalance that affects the growth and development.

I base this off the fact that, in humans, there are no known viable complete autosomal monosomies (Cri du Chat syndrome is a partial monosomy of chromosome 5) and only the three previously mentioned trisomies. Just because we never see individuals with monosomies or trisomies other than the ones mentioned absolutely does not mean they don't occur, but rather, that they are completely non-compatible with even advanced intra-uterine age, let alone extra-uterine viability.

Further, in humans, more than 80% of all conceptions never make it to term, and roughly 50% of all conceptions have some sort of chromosomal anomaly that makes the pregnancy non-viable. It doesn't even necessarily have to be gross chromosomal abnormalities, as significant micro-deletions of chromosomes in the right places can create a non-viable pregnancy. Most often the pregnancy is spontaneously aborted within the first 4-6 weeks and so the woman doesn't even realize she's pregnant. (Not to open a can of worms, but these facts are one of my biggest arguments against the "life begins at conception" crowd).

[cheerfulgreek]

Originally Posted by BigRedBeta

It's not that the mother's body rejects it, it's that the having either extra information (an extra chromosome hanging out) or missing information (having only one chromosome when you should have two) results in a non-viable fetus. This would be due to having too much or too little of needed protein or some other form of imbalance that affects the growth and development.

I base this off the fact that, in humans, there are no known viable complete autosomal monosomies (Cri du Chat syndrome is a partial monosomy of chromosome 5) and only the three previously mentioned trisomies. Just because we never see individuals with monosomies or trisomies other than the ones mentioned absolutely does not mean they don't occur, but rather, that they are completely non-compatible with even advanced intra-uterine age, let alone extra-uterine viability.

Further, in humans, more than 80% of all conceptions never make it to term, and roughly 50% of all conceptions have some sort of chromosomal anomaly that makes the pregnancy non-viable. It doesn't even necessarily have to be gross chromosomal abnormalities, as significant micro-deletions of chromosomes in the right places can create a non-viable pregnancy. Most often the pregnancy is spontaneously aborted within the first 4-6 weeks and so the woman doesn't even realize she's pregnant. (Not to open a can of worms, but these facts are one of my biggest arguments against the "life begins at conception" crowd).

Thanks for this.

[AKA_Monet]

Originally Posted by BigRedBeta

It's not that the mother's body rejects it, it's that the having either extra information (an extra chromosome hanging out) or missing information (having only one chromosome when you should have two) results in a non-viable fetus. This would be due to having too much or too little of needed protein or some other form of imbalance that affects the growth and development.

I base this off the fact that, in humans, there are no known viable complete autosomal monosomies (Cri du Chat syndrome is a partial monosomy of chromosome 5) and only the three previously mentioned trisomies. Just because we never see individuals with monosomies or trisomies other than the ones mentioned absolutely does not mean they don't occur, but rather, that they are completely non-compatible with even advanced intra-uterine age, let alone extra-uterine viability.

Further, in humans, more than 80% of all conceptions never make it to term, and roughly 50% of all conceptions have some sort of chromosomal anomaly that makes the pregnancy non-viable. It doesn't even necessarily have to be gross chromosomal abnormalities, as significant micro-deletions of chromosomes in the right places can create a non-viable pregnancy. Most often the pregnancy is spontaneously aborted within the first 4-6 weeks and so the woman doesn't even realize she's pregnant. (Not to open a can of worms, but these facts are one of my biggest arguments against the "life begins at conception" crowd).

So what are the physicians calling the Turner's Syndrome and the Philadelphia chromosome in Fragile X these days?

Just asking because I haven't kept up with that research.

Cheerful

The fertilized eggs are hypermethylated and the heterochromatin is wacky causing inappropriate crossovers and non-homologous end joining in the chromosomes.

Remember human eggs are EXTREMELY fragile unlike say mouse. Knockout/trangenics are rather difficult to do even with similar non-human primate species. And OLAW rules will NOT allow researchers to use chimps for molecular studies. The highest we researchers can get these days are baboons. But since NIH eliminated our budgets, doubtful anyone can pay for it... Even med and vet schools are are having difficulties with the animals they use for teaching...

[BigRedBeta]

Originally Posted by AKA_Monet

So what are the physicians calling the Turner's Syndrome and the Philadelphia chromosome in Fragile X these days?

Just asking because I haven't kept up with that research.

Just to make it clear - I said there are no "autosomal monosomies" - which leaves your Turner's out of the picture.

The Philadelphia chromosome (I'm not sure what you're getting at with it's relation to Fragile X - I've never heard of any association, which doesn't mean it's not out there) as a balanced translocation technically wouldn't fit the general idea of monosomies or trisomies as all the information is there (nor are there extra copies), just in an abnormal configuration...

As for the expanding tri-nucleotide repeats in Fragile X (CAG, right?)...as far as I'm aware it's a non-coding region.

[cheerfulgreek]

Originally Posted by AKA_Monet

Cheerful

The fertilized eggs are hypermethylated and the heterochromatin is wacky causing inappropriate crossovers and non-homologous end joining in the chromosomes.

Remember human eggs are EXTREMELY fragile unlike say mouse. Knockout/trangenics are rather difficult to do even with similar non-human primate species. And OLAW rules will NOT allow researchers to use chimps for molecular studies. The highest we researchers can get these days are baboons. But since NIH eliminated our budgets, doubtful anyone can pay for it... Even med and vet schools are are having difficulties with the animals they use for teaching...

Well, I know that OLAW does a lot of the monitoring and keeps everything compliant, but aren't there other alternatives? What about PGD? I know it requires in vitro fertilization and all, but with it, through research, wouldn't scientist be able to actually do genetic tests on cells and DNA removed from an embryo, and then return the embryo to the womb?