WHAT if a male child who had it reproduced, would it be a 100% chance for his male and female children to have/carry it, or would it unmanifest/wipe itself out somehow? We know that a female bloodline could carry it forever.
In the end, Okonkwo threw the Cat.
I have not read enough of the disease, but based on the movie, the physician explained it as a sex-linked disease. Since the mother is a carrier and the son is affected by the disease, it means that the gene can be found in the x-chromosome (x from the mother and y from the father).
If the child who was affected by the disease was able to reproduce, his daughter(s) would be a carrier while his son(s) will not be affected (since he donates the x-chromosome to his daughter(s) and y-chromosomes to his son(s)).
Also, in the movie, they explained that the disease affect them at an early age. Before any treatments were discovered, they were not able to live at a stage where they had a chance to reproduce. As more research were conducted, they have a better understanding of the disease.
One of Michealia's sisters was not a carrier. We get one X from our mothers and one X from our fathers. If we get the good X from our mother who is a carrier then we would not have it unless we got a bad X from our father. That's my understanding.
I always liked the way a scraped knee looks on a girl. - Mrs. Harker
WHAT if a male child who had it reproduced, would it be a 100% chance for his male and female children to have/carry it, or would it unmanifest/wipe itself out somehow?
Males don't pass it on at all. Only the women do. At least, that's the impression I got.
The only way to really breed it out would be for all the carriers to refrain from reproducing and let their "poisoned blood" (as the father called it in this movie) die with them. If they don't have children, then obviously they can't pass on the disease and the problem is solved. However, this solution is delving into the realm of eugenics, which is a whole 'nother kettle o' fish.
Cross my heart, smack me dead, stick a lobster on my head.
"Breeding out" is a term that reminds me of the Holocaust and the intentions of many who desperately tried to wipe out a hell of a lot of people to reach a cruel and twisted goal of "genetic purity..."
Sex linked conditions like ALD - and BTW a point of actual fact is this goes for all the dystrophies - cannot be "bred out." There is no way of removing the genetic abnormality because its only half of the equation - females are carries not sufferers, and although there are a few cases of girls who have developed ALD its VERY rare.
Absolutely ALD could be bred out. For example in the movie, of the three sisters two are carriers (genetic tests can be performed to identify who in the family is a carrier), if neither of the carriers were allowed to breed then the disease would die out in their lineage and the remaining sister could still pass pass her genetic material into subsequent generations. This would effectively breed out the disease in the family. Unfortunately, it does conjure images of Nazi Germany...
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I liked the idea of finding the enzyme that is missing or not enough in ALD, and synthesizing it and giving it to all the ALD patients. The women could use it too, because things can get pretty awful for them even if they don't get as bad as the boys do.
Let's just say that God doesn't believe in me.
I wonder how hard it is to find particular microscopic enzymes? I know it's hard, but I wonder how miserable it is. Crap it's hard enough to make anything out on an ultrasound, let alone a bacteria.
In the end, Okonkwo threw the Cat.
It could be possible to "breed out" the disease, by not allowing carriers and affected males to pass on their genes.
Most males who are affected by ADL, are affected at an early age and die before the reach sexual maturity or are so incapacitated by their debilitating disease that they cannot reproduce.
But hypothetically speaking, if it were possible for an affected male to reproduce, his male progeny would not have the disease, and all his female progeny would be carriers. ADL is sex-linked on the x-chromosome.
So it could be done. This could go the way of Smallpox.
In the end, Okonkwo threw the Cat.
no, not really. ald cannot go the way of smallpox. smallpox was eradicated by vaccination--it was a disease caused by a virus. ald is a genetic disease, so while it could possibly be bred out where there are no affected symptomatic individuals, that possibly could only arise if we lived in a Hitler-esque totalitarianistic state where people with the disease were not allowed to procreate. ald cannot be eradicated by vaccination because it is genetic. barring that Hitler-esque society (impossible scenario), the (mutated) genes for the disease will always be present in a population. genetic disease can NEVER be eradicated. no offense, but that's just common sense.
shareI didn't mean to vaccinate against it, that's stupid.
In the end, Okonkwo threw the Cat.
Did you hear of haemophilia? And the case of Queen Victoria as "The Grandmother of Europe" spreading it through all the royal families in Europe? We learned about her as the example of X-chromosome diseases in 9th grade and later again in 12th or 13th grade.
That's why I found the "only mothers can pass it down" so peculiar at first, until I realised that is because this disease is so severe, it kills the boys before they can reproduce!
The principle of all these x-chromosome transmitted diseases should be as follows:
Women with ONE ill x-chromosome (x') are lucky because their other healthy chromosome (x) balances it out and they do not get sick. Men don't have another one, that's why they always get sick. This is also why a disease like this could never be transmitted on the y-chromosome. Y-chromosome traits are light, such as long hairs growing out of a man's nose, if I remember correctly.
That being said, men have two types of sperm, one with y and one with x chromosomes. Women have two types of eggs of x-chromosomes, which usually do not differ.
1.
Sick man(x'y)and healthy woman(xx)
If he gives his y to any x the results are always xy (healthy man)
If he gives his x' to any x the results are always x'x (carrier woman)
There is a 50:50 chance between these two options.
2.
Carrier woman(x'x)and healthy man(xy)
50:50 chance between x'x and xx (Carrier or healthy woman)
AND 50:50 chance between x'y and xy (Sick or healthy man)
Now there is a possibility for sick women:
3.
Carrier woman(x'x)and sick man(x'y)
50:50 chance between x'y and xy (Sick or healthy man)
AND 50:50 chance between x'x and x'x' (Carrier or sick woman)
If you have a sick woman,there are two more options:
4. Sick woman(x'x')and healthy man(xy)
50:50 chance between x'x and x'y (Carrier woman or sick man)
And finally:
5. Sick woman(x'x')and sick man(x'y)
50:50 chance between x'x'and x'y (Sick woman or sick man)
To outbreed it I suggest to let the ill males father as many healthy boys and carrier girls as he wants. You could try to only have boys, but that's not that easy to do. The only way would be killing the female embryos via abortion. Or in artificial fertilization you have to wait until after the fertilization to know the gender, because you cannot completely seperate the chromosomes in the sperm.
A carrier woman could use artificial fertilization. When her eggs are outside, I guess you could examine if it is one of the healthy half or sick half of eggs.
Then you could be sure to have a healthy eggs and no restrictions on the gender.
One thing I hated was the stupid mother blaming herself for the toss of a coin she had no power over. By that logic EVERY man should be blamed for the unwanted gender of a child. You could also blame this father for not giving his x-chromosome to produce a healthy girl.
And if a healthy egg had been used, they would not have this very specific child either, with over 6 billion possibilities of combination. So stop blaming yourself!
Thanks for spelling it out like that, I understand now. I'm kind of visual, it has to be laid out carefully like that for me to get it x_x Chromosome pattersn remind me of math, and I tweek out when I deal with math.
It IS technically possible, but it would be hugely complicated and expensive, not to mention delving into immoral.
And her flipping out so much did get a little old. *beep* happens, mate!
And thanks for going to the trouble on an old-ass thread :) I enjoyed reading it.
In the end, Okonkwo threw the Cat.
No problem, I liked thinking about it.
Genetics are fun; but I get confused with the mathematical aspect of it, too. Especially when it comes to the laws of Mendelian inheritance. Dominant and recessive traits wich are not linked to the sex chromosomes.
I realised while doing it that a carrier woman and a sick man do not increase the risk for boys when compared to carrier woman and healthy man. I bet most people would bet otherwise. :)
Another thing, I remembered there are men that can have xxy-chromosomes. (Just as there are xyy men and xxx women. Or even rarer xxyy or xxxx)
Now I'm wondering what would happen if the mother was also a carrier? Would this boy's x balance out the x' as well?
I could not find an answer to this question. But I want to know, dammit!
And now I'm wondering what sperm relation these xxy men produce. Two thirds x and one third y?
And if they are x'xy will they have on third x', one third x and one y?
I guess if I were a carrier woman of a disease I would go for artificial fertilization, anyway and not risk conceiving sick boys, or more carrier girls. Make sure only the healthy eggs are used. And THEN let nature run its course. This would not be immoral because you do not kill a fertilized egg, or embryo. I'm not sure how expensive this egg-checking would be, but I'm certain it could be done.
I don't know if you can screen the individual ovum, can you take a specific sample out of something that small?
http://bioethics.georgetown.edu/pcbe/reports/reproductionandresponsibility/chapter3.html
I know they can check the fetus AFTER it got started, and they can take a DNA sample from you and check the LIKELYHOOD of a genetic disease. But I think pre-screening eggs is still on the horizon
In the end, Okonkwo threw the Cat.
Modern medicine has ruined natural selection. It's not a good thing to save someone with a genetic defect so they can reproduce and pass it on.
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