Genetic Research

[Christina]

Maybe this should go in the Science forum but most of my questions are too lightweight for that. Feel free to move it if you want to.

I read and hear a lot about how certain genes are being identified that are related to different medical problems and disorders and that sounds like a very good thing, but what happens next? I assume (probably erroneously) that they would then be able to test for that gene or combination of genes that indicates at least the potential to have that medical problem, but how is that knowledge used? Is the intent to screen for the disorder in fetuses while an abortion is still viable or is it supposed to lead to a cure for people that have it?

[BioBeing]

Maybe this should go in the Science forum but most of my questions are too lightweight for that. Feel free to move it if you want to.

I read and hear a lot about how certain genes are being identified that are related to different medical problems and disorders and that sounds like a very good thing, but what happens next? I assume (probably erroneously) that they would then be able to test for that gene or combination of genes that indicates at least the potential to have that medical problem, but how is that knowledge used? Is the intent to screen for the disorder in fetuses while an abortion is still viable or is it supposed to lead to a cure for people that have it?

It’s a good question. Most people (and reporters) don’t really understand “genetic research” because, in part at least, it means different things to different researchers.

Most of the time when the press say researchers have identified a gene for X, ignore them.

Not only that, but what they are actually looking for are mutations in a gene that correlate with the phenotype. We all (for the most part, and sex chromosomes aside for now) have the same basic set of genes: it is the very small changes in those genes that make the difference. You may (if you are lucky) hear these more properly called alleles. An allele is basically a particular form of a gene.

What the researchers have done most of the time is identify a gene (allele) that is involved in a particular process, and very rarely do genes act alone. There is no single gene for “cancer” or “gay”. When you hear of a gene for breast cancer, what is meant is an allele (or set of alleles) that is/are implicated to play a role somewhere in the pathway to develop breast cancer. The gene itself is going to be present in the healthy population – it is the distribution of the changes that the researchers are studying.

What the researchers are trying to do is to identify which alleles correlate with a given disease. p53 was "gene of the year" a few years ago because about half of all cancers have mutations in p53. The p53 protein (the product of the p53 gene) is a key regulator in many aspects of cell division. But a mutation in p53 is not the whole story. Other genes have to go bad too to make a cancer. And that "other" gene (or genes) often defines what type of cancer forms, how aggressive it is etc. Some of these alleles you will get from your parents, making you predisposed to a certain disease. Others are somatic mutations that occur duting your lifetime. So being predisposed does not mean you will automatically get the disease. A woman predisposed to breast cancer can increase her chances of not getting the disease by not doing things like smoking that are known to increase the risk of the secondary mutations within her body necessary for the cancer to form. [IIRC, these are in genes like Bcr-able?]

Mutations/alleles you inherit from your parents could be screened for during gestation. And many are. Down’s Syndrome, of course, being an obvious example. This is where you have a whole extra copy of one chromosome, so is easy to see in a microscope slide, and correlates very highly with the syndrome. Heck, even the X/Y chromosome complement have been used to determine if a fetus should be aborted.

In most cases though, correlation between a specific allele and a given disease is not 100%. So using this information alone to determine whether to terminate a pregnancy, or have breast removal surgery, is risky. Such decisions should be made with competent genetic counseling by someone who knows the other actors involved.

Other uses of genetic screening, at least as envisionaged, are for personalized healthcare. Different people metabolize drugs in different ways, and this could be exploited in deciding what drugs to prescribe. Some cancers can be treated by some drugs, while cancers which appear very similar in the clinic might be resistant. Knowing the exact genetic nature of the cancer can lead to the correct treatment.

Anyway - that is just a short answer. I'm sure I mangled some areas and short changed others, so do not take this as medical advise!

[Christina]

Thanks - that was exactly the level of answer I was hoping for and it was a more general question than what pertains to my disorder. I'm almost 50 and certainly not hoping for a cure in my lifetime and it's way too late to abort me. I just wanted to understand what the intent and possibilities of genetic research are in general.

[Berthold]

If* individual genome analysis becomes an inexpensive routine, one of the things bound to happen will be that private health insurers will use it to calculate risks and adjust their individual fees (which they already do now, but with more "primitive" methods).

*Richard Dawkins thinks it to be plausible, and has discussed possible consequences (if only I remembered in which of his books ;)).

[Ray Moscow]

One's genetic information could easily be misused, too. For example, if it became known (or suspected) that you had a genetic tendency to certain diseases, you could be denied health or life insurance on that basis, or even employment.

ETA: Oh, Berthold's said as much already.

[Christina]

Yeah. I was concerned that mine would be considered a pre-existing condition when retired and was no longer covered by the employee group plan, but I was able to transfer my existing policy over to the CalPERS group plan without any review. That sure was a relief. I have to get new life insurance soon and I'm not sure how it will affect it if at all.

[BioBeing]

Ethics, and regulations, often have to play catch up with the science. Insurance companies will try to get away with whatever they can, unless regulations get put in place telling them they cannot.

[Sodong]

Maybe this should go in the Science forum but most of my questions are too lightweight for that. Feel free to move it if you want to.

I read and hear a lot about how certain genes are being identified that are related to different medical problems and disorders and that sounds like a very good thing, but what happens next? I assume (probably erroneously) that they would then be able to test for that gene or combination of genes that indicates at least the potential to have that medical problem, but how is that knowledge used? Is the intent to screen for the disorder in fetuses while an abortion is still viable or is it supposed to lead to a cure for people that have it?I would expect lots of the research is directed at developing gene therapies for various diseases and conditions. There's a readable and informative document here (http://www.ornl.gov/sci/techresources/Human_Genome/medicine/genetherapy.shtml) from the Human Genome Project Information site that outlines the current status of the research.

What the researchers are trying to do is to identify which alleles correlate with a given disease. p53 was "gene of the year" a few years ago because about half of all cancers have mutations in p53. The p53 protein (the product of the p53 gene) is a key regulator in many aspects of cell division.There's a nice discussion of this here (http://carcin.oxfordjournals.org/cgi/content/abstract/25/6/857) but more to the point check out the list of citations at the bottom of that page and here (http://ajp.amjpathol.org/cgi/content/abstract/161/4/1199), for example to get an appreciation of how research into this gene family covers a broad range of human health problems, albeit in very complex ways.

[Zygote]

This is another strong argument in favor of National Health Care. If everyone is covered, pre-existing conditions won't be a liability for jobs or insurance. As it is, some people are reluctant to seek diagnosis or even screening or fear that they will be branded with a pre-existing condition that will render them uninsurable.

My son has Type 1 diabetes. A predisposition for this arises with certain combinations of the various alleles out there. Another combination confers some protection against developing it. Families with multiple children with Type 1 may have their children screened for their allele combinations. There are some experimental treatments which may act to postpone onset and therefore delay complications.

My niece has a severe genetic neurological disorder. Genetic research found that it is due to a stutter at the beginning of both of her copies of the gene for a certain enzyme. Research goes towards finding a way to replace that enzyme. Her brothers, and probably my children as well, will seek testing before reproducing to see if they are carriers.

Preventive screening is already here. My husband's doctor just started offering it. It screens for the most prevalent known genetic markers and lets work be done in advance to prevent, postpone or mitigate the possible difficulties from any disorders.

[Lisa0315]

Interesting!

[Berthold]

This (http://en.wikipedia.org/wiki/Huntington's_disease) :eek: has been known for some time now. One of the cases where prevention is feasible, and, I suppose, no one (except some nuts) would find it morally questionable.

[Christina]

Interesting!

I'm glad that I asked and read these links because I understand it a lot better now and can see why it's so difficult when multiple genes are involved. Maybe someday it will lead to something that can correct things or at least detect them early.

[Lisa0315]

Interesting!

I'm glad that I asked and read these links because I understand it a lot better now and can see why it's so difficult when multiple genes are involved. Maybe someday it will lead to something that can correct things or at least detect them early.

Genetics fascinates me. I have thought for some time that genetics may very well eliminate discrimination in the world. Imagine how many people might be surprised to find out that they are black, or white, or Arab, or Jew? Can you imagine if Osama bin Laden found out he was 20% Jew or if skinheads and KKK found out that they were 10% black?

I am a mutt and proud of that fact. Yet, having been raised in the South as white, I have heard every N joke there is. It is disgusting to me.

Naturally, early detection and cure for disease is just as important as this, but I wonder how much hatred in this world, and how many senseless deaths via war could be eliminated if we all knew that we are all the same. Race, creed, religion, none of it matters. We are simply Earthlings, human beings, that's it.

Lisa

[nygreenguy]

Genetics fascinates me. I have thought for some time that genetics may very well eliminate discrimination in the world. Imagine how many people might be surprised to find out that they are black, or white, or Arab, or Jew? Can you imagine if Osama bin Laden found out he was 20% Jew or if skinheads and KKK found out that they were 10% black? Actually, most genetics cant tell you this. Many times african american DNA can be closer to european DNA than to other africans! There are some markers that you can trace, but I dont think it goes much beyond that.

[Lisa0315]

Genetics fascinates me. I have thought for some time that genetics may very well eliminate discrimination in the world. Imagine how many people might be surprised to find out that they are black, or white, or Arab, or Jew? Can you imagine if Osama bin Laden found out he was 20% Jew or if skinheads and KKK found out that they were 10% black? Actually, most genetics cant tell you this. Many times african american DNA can be closer to european DNA than to other africans! There are some markers that you can trace, but I dont think it goes much beyond that.

Yeah, but they are working on databases so that they can trace people back to African tribes. It is not really there yet, but in twenty years or so, I suspect that we will be able to test Jews for their lost tribal heritage, point to African descendents, and so forth.

Lisa

[David B]

Genetics fascinates me. I have thought for some time that genetics may very well eliminate discrimination in the world. Imagine how many people might be surprised to find out that they are black, or white, or Arab, or Jew? Can you imagine if Osama bin Laden found out he was 20% Jew or if skinheads and KKK found out that they were 10% black? Actually, most genetics cant tell you this. Many times african american DNA can be closer to european DNA than to other africans! There are some markers that you can trace, but I dont think it goes much beyond that.

Yeah, but they are working on databases so that they can trace people back to African tribes. It is not really there yet, but in twenty years or so, I suspect that we will be able to test Jews for their lost tribal heritage, point to African descendents, and so forth.

Lisa

If testing reaches that sort of standard, my guess is that we will find that lots of Jews aren't really very Jewish at all, in genetic terms, and those that are will prove pretty much genetically identical to the Palestinians that they have been displacing from their homes and lands, and killing, in the name of their mad religion.

David

[Notta]

We're ALL descendants of Africans, Lisa.

If you take any two individuals at random from the human population, chances are they'll be more alike than any two individuals from the same 'race.'

'Race', in genetic terms, is meaningless. We can't tell from DNA evidence if someone is African, Asian, European, Native American, or what, unless we look for evidence of genetic abnormalities that are found more frequently in a certain sub-set of a population (Tay-Sachs disease, for one, in a sub-set of Jews), but even THAT can't tell you someone's 'race' or ethnicity, because the same genes can be found in someone who doesn't have that ethnic background.

[Christina]

'Race', in genetic terms, is meaningless.

Race has always been a fuzzy concept to me at best and seems to mostly be a polite euphemism for skin color. Was it ever a meaningful term used in a scientific capacity?

[Lisa0315]

Actually, most genetics cant tell you this. Many times african american DNA can be closer to european DNA than to other africans! There are some markers that you can trace, but I dont think it goes much beyond that.

Yeah, but they are working on databases so that they can trace people back to African tribes. It is not really there yet, but in twenty years or so, I suspect that we will be able to test Jews for their lost tribal heritage, point to African descendents, and so forth.

Lisa

If testing reaches that sort of standard, my guess is that we will find that lots of Jews aren't really very Jewish at all, in genetic terms, and those that are will prove pretty much genetically identical to the Palestinians that they have been displacing from their homes and lands, and killing, in the name of their mad religion.

David

Perhaps, but same goes for Arabs.

[David B]

Yeah, but they are working on databases so that they can trace people back to African tribes. It is not really there yet, but in twenty years or so, I suspect that we will be able to test Jews for their lost tribal heritage, point to African descendents, and so forth.

Lisa

If testing reaches that sort of standard, my guess is that we will find that lots of Jews aren't really very Jewish at all, in genetic terms, and those that are will prove pretty much genetically identical to the Palestinians that they have been displacing from their homes and lands, and killing, in the name of their mad religion.

David

Perhaps, but same goes for Arabs.

Similar, certainly. But there hasn't, AFAIK, been the same sort of diaspora among the Arabs of the Eastern Mediterranean area that there has been for followers of Judaism. The diaspora gives all sorts of opportunities for genetic mixing, licit or otherwise, that were not available to those who just sat tight.

It's pretty clear, I think, that the inhabitants of that area of the order of three or four thousand years ago were pretty much of the same stock.

The idea that the Jews are the descendants of those who allegedly came out of Egypt with Moses are pretty much busted, AFAIK.

David

David