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| Topic: Genetics and predicting diseases | |
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http://news.bbc.co.uk/2/hi/health/8652583.stm
US scientist has genome screened for disease risk
By Helen Briggs Health reporter, BBC News This man knows his genetic destiny A US scientist has had all his DNA screened for genes which predict the diseases he may develop in later life. Stephen Quake's genetic profile was probed for genes linked to dozens of diseases, such as cancer and diabetes. The healthy 40-year-old was told he was at increased risk of heart attack, diabetes and some cancers. Scientists say the study, published in the Lancet, ushers in a new era of personalised medicine, but raises ethical dilemmas. Professor Quake received publicity last year when he used new technology to sequence his entire genetic code, or genome, for less than 50,000 US dollars (£33,000). This was a relatively cheap figure compared with early genome sequencing efforts. The professor of bioengineering volunteered to have his genetic map analysed for genetic "mistakes" and variations known to be associated with 55 conditions. The experience with Steve Quake's genome shows we need to start thinking - hard and soon - about how we can deal with that information. They included a rare heart condition that appeared to run in the family. Before taking the test, he was given counselling to prepare him for the possibility that a serious disease could be uncovered. The results were mixed. They showed he has a much lower than expected risk of developing Alzheimer's disease in his lifetime. But he also has a much higher risk of getting obesity, diabetes and coronary heart disease. He also has rare genetic variations associated with sudden cardiac death. Professor Quake, of Stanford University, California, said: "It's certainly been interesting. I was curious to see what would show up. "But it's important to recognise that not everyone will want to know the intimate details of their genome, and it's entirely possible that this group will be the majority. "There are many ethical, educational and policy questions that need to be addressed going forward." The falling cost of genome sequencing is bringing us closer to the day when it is accessible to all. WHAT THE SCIENTISTS DID Entire genome sequenced and published in August 2009 Information on genetic variations (SNPs) that have effects on specific diseases catalogued in database Genetic data overlaid on Quake's genome Computer calculates risk of a certain disease based on genome sequence and inherent risk from his age and gender Some scientists believe similar genetic assessments could be offered by doctors in about a decade. Professor Henry Greely, from Stanford Law School, said doctors are about to be hit by a "tsunami" of genome sequence data. He said: "The experience with Steve Quake's genome shows we need to start thinking - hard and soon - about how we can deal with that information." More than 10 individuals have had their full genomes sequenced. Some have been analysed for genetic variations that are associated with certain diseases. And a number of companies offer genetic tests to assess the risk of a range of conditions without sequencing a person's full genome. But the Stanford team went further - honing in on Professor Quake's family history of heart problems. Dr Philippa Brice of the genetic think-tank Population Health Genomics told the BBC: "In the case of this specific example the research is not ground breaking. "Its significance lies in the way it illustrates the potential future of genomic medicine whereby doctors will be able to use this as a useful clinical approach." |
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The problem with screening for genetic diseases is that many genes can contribute to the overall phenotype. Not to mention environmental factors. Like Diabetes, both 1 and 2 have around 800 genes which can potentiate the disease, or help it start. It's not easy to predict this stuff.
Not to mention even though the genome has been sequenced, we don't yet know what over 30% of the protein coding genes actually code for, or how single nucleotide polymorphisms will affect those genes. |
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The problem with screening for genetic diseases is that many genes can contribute to the overall phenotype. Not to mention environmental factors. Like Diabetes, both 1 and 2 have around 800 genes which can potentiate the disease, or help it start. It's not easy to predict this stuff. Not to mention even though the genome has been sequenced, we don't yet know what over 30% of the protein coding genes actually code for, or how single nucleotide polymorphisms will affect those genes. Great contribution - this sounds about right to me. Of course different diseases/afflictions have different degrees of complexity in ways that genetics contributes to the disease - some diseases will be very easy to predict accurately, and others will always have the 'lifestyle' component overshadow the genetic component. But for those with more of a genetic influence (and less lifestyle) and yet a very complex interplay of genes - I still think we will eventually be able to predict this accurately - and long before we understand the mechanisms (we may not know exactly why a particular gene contributes to the condition). We will have databases with millions of genomes, and decades of life history for those people, and will simply find statistical correlations. |
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It's great that we're able to do this - albeit with not a very high degree of certainty or predictability yet. The problem will come in at the point of use: HOW will this information be used? WHO will use it? WHO will be able to access it? WHEN will it be used? WHY will it be used? WHERE will it be used? For as many beneficial applications as may be possible, there are an equal or greater number of MIS-applications of this kind of information in the wrong hands. The old truth still applies: If a technology CAN be misused, it WILL be misused.
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Edited by
georgeknows
on
Sat 05/08/10 08:03 AM
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If a technology CAN be misused, it WILL be misused. Indeed, but that's not a reason to abandon it. By that logic we shouldn't drive cars because they have been used to run people down. We shouldn't travel by air because of 9/11. Oh and we shouldn't use the internet because it's aided in conspiracies, pedophilia and terrorism. Oh and to OP, I agree, eventually we'll have a much more accurate way of predicting, just at the moment, the cost of the research isn't equivalent to the benefits. Chances are it will be abandoned and then taken up again in the near future when genetic techniques are much cheaper and more efficient. |
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Not suggesting that it not proceed ... just saying that a high degree of skepticism be employed when listening to people who only stress how 'good' it will be while ignoring the potential for misuse ... every slope has a varying degree of slipperiness, but they're ALL slippery at some point ...
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The technology is progressing much faster than anyone dreamed twenty years ago. As the cost goes down many more people will be screened for genetic issues and gene therapy is not that far behind. You may be given a retrovirus in the future that stops allergies, lessens the trend to gain weight, prevents cancer, and stops the formation of plaque that causes Alzheimer... and many more.
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True. All valid points. People may also, however, be denied employment, insurance, etc - all because an individual is 'genetically predisposed' to certain risks the employer or insurer would rather not be bothered with ...
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Insurance companies (and employers - though more in the case of buying life insurance of their employees) are already doing that with diabetes and cancer, as two examples.
But if we know about it, and can come up with cures or other ways to negate the possibility of the genetics involved, which would negate an insurance company from saying no. |
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Edited by
Kings_Knight
on
Sat 05/08/10 12:40 PM
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That's true ... but what about those cases where there's no cure or viable therapy for the disease? Let's say 'Reyes' or 'Downs' ... or, at this point, Alzheimers. There are going to be distinctive genetic markers and sequences to indicate the possibility that the disease may present at some later date in life, but has not yet manifested via symptomatology. In those cases, where the cure or the 'gene therapy' hasn't yet caught up to the diagnosis, the most likely course of action for an employer or insurer will be (not 'might be') to deny employment or insurance. What recourse will the people denied have? None. People in this category are also likely to be the majority, not the minority, of cases for quite some time. There's no reason to believe they'll be given 'equal' status with those having applicable therapies - which means they will be (here's that word) discriminated against in favor of a 'healthy' person. And so we go down the slippery slope ... but that's no reason to not pursue these therapies. How would you handle the problems these markers will automatically create (by their existence) for people in the 'untreatable' category?
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Edited by
SkyHook5652
on
Sun 05/09/10 01:59 PM
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I'm not up on this whole area, but I have a question...Are these "links" 100% reliable? That is, does everyone with a certain marker develop that particular disease? And the flip side of that same coin, does anyone without the marker ever develop the disease? If not, then we have the potential for a situation where someone gets the gene therapy and still develops the disease.
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I'm not up on this whole area, but I have a question...Are these "links" 100% reliable? That is, does everyone with a certain marker develop that particular disease? And the flip side of that same coin, does anyone without the marker ever develop the disease? If not, then we have the potential for a situation where someone gets the gene therapy and still develops the disease. I think the answer depends on the disease/condition being considered; but I would expect that some people would get some of the diseases/conditions even after receiving gene therapy. In most cases, both therapies and lifestyle changes are designed to reduce risk (sometimes tremendously), not achieve a guaranteed protection. |
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That's true ... but what about those cases where there's no cure or viable therapy for the disease? Let's say 'Reyes' or 'Downs' ... or, at this point, Alzheimers. There are going to be distinctive genetic markers and sequences to indicate the possibility that the disease may present at some later date in life, but has not yet manifested via symptomatology. In those cases, where the cure or the 'gene therapy' hasn't yet caught up to the diagnosis, the most likely course of action for an employer or insurer will be (not 'might be') to deny employment or insurance. What recourse will the people denied have? None. People in this category are also likely to be the majority, not the minority, of cases for quite some time. There's no reason to believe they'll be given 'equal' status with those having applicable therapies - which means they will be (here's that word) discriminated against in favor of a 'healthy' person. And so we go down the slippery slope ... but that's no reason to not pursue these therapies. How would you handle the problems these markers will automatically create (by their existence) for people in the 'untreatable' category? If there's a wider pool of people who are volunteering to do this, then I would think it would actually help to find cures, or ways to shut off the genes that "might" trigger on for Alzheimers, Reyes, etc. I know mom's Multiple Sclerosis has several groups that are trying to get together entire families to find out what triggers, and what may show up in the next generation. Since I'm against the health "insurance" and for health "care", I believe the push for health care needs to be done. If everyone is taken care of, then there's no need for insurance. SkyHook, no, not everyone with the marker develops it. However, it does allow a person to decide if it's something they wish to risk passing on to their children. Using MS again, mom has it, it generally runs along the female side, I may never manifest it, however, I stand the very real chance of passing it on to any children, should I choose to have any. And like massagetrade said, it allows for lifestyle changes. |
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