tag:blogger.com,1999:blog-1812431336777691886.post933954321236844664..comments2024-02-29T03:57:00.088-05:00Comments on The Mermaid's Tale: GWAS revisited: vanishing returns at expanding costs?Anne Buchananhttp://www.blogger.com/profile/09212151396672651221noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-1812431336777691886.post-4346766477943669752013-07-03T15:35:07.401-04:002013-07-03T15:35:07.401-04:00Fair enough. This was 2009, so one should check a...Fair enough. This was 2009, so one should check any later reports to see if the picture has changed.Ken Weisshttps://www.blogger.com/profile/02049713123559138421noreply@blogger.comtag:blogger.com,1999:blog-1812431336777691886.post-48194644728713207592013-07-03T15:34:30.669-04:002013-07-03T15:34:30.669-04:00You're right, this was lazy of us.You're right, this was lazy of us. Anne Buchananhttps://www.blogger.com/profile/09212151396672651221noreply@blogger.comtag:blogger.com,1999:blog-1812431336777691886.post-31761209393671185282013-07-03T11:53:36.989-04:002013-07-03T11:53:36.989-04:00" By far the major risk factor for most diabe..." By far the major risk factor for most diabetes, for example, involves energy and fat metabolic pathways. Individuals at risk can already target those pathways in simple, direct ways: walk rather than taking the elevator, and don't over-eat"<br /><br />No. What you meant to say was "..By far the major risk factor for most TYPE II diabetes,.."<br /><br />Please be accurate. Believe me, children with type I diabetes get REALLY pissed off by this lazy, inaccurate but widespread confusion. Being told that their autoimmune condition is caused by over-eating or not walking, and by implication that they brought it on themselves is a misunderstanding that would be bad enough coming from a junk TV show. But coming from someone who claims to be an expert on genetics is seriously uncool.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1812431336777691886.post-3849338006169034602009-04-23T09:50:00.000-04:002009-04-23T09:50:00.000-04:00Jennifer, In my #1 part of my response I said gene...Jennifer, In my #1 part of my response I said genetics is important in two ways, but I only mentioned one of them--that genes are functional aspects of life and affect our traits.<br /><br />The second way is that genetic _variation_ is associated with trait variation.<br /><br />Both usually apply to varying extents.<br /><br />There is actually a third way, that is not widely considered, which is that all of your cells have a slightly different genome. That's because every time a cell divides, which has been happening since you were a single cell (a fertilized egg), some mutations occur. So each person has variation they inherited in their fertilized egg, and variation that has accumulated among their cells. How important that can be depends on the circumstances, but it can be vital (as it is, for example, in cancers)Ken Weisshttps://www.blogger.com/profile/02049713123559138421noreply@blogger.comtag:blogger.com,1999:blog-1812431336777691886.post-73007996611998384102009-04-23T09:22:00.000-04:002009-04-23T09:22:00.000-04:00Jennifer--
These are all the right questions! And...Jennifer--<br />These are all the right questions! And nobody has the answers! But here are some reactions:<br /><br />1. Of course genetics plays a part, in two ways. Gene action is involved in all body functions.<br /><br />2. Gene function involves response to environment, which can include all sorts of things, such as diet and activity. The word 'interaction' is used in various ways. Sometimes it means just that you are the sum of what you inherited and what you do. Sometimes it means that depending on the particular genetic variation that you carry, the same environment can have different effects. In many or most cases these two kinds of interaction are not critically to the kinds of questions you ask.<br /><br />3. Anyone can get fat by too much dietary intake and storage, and not enough energy expenditure such as by activity. This is not unique to humans (ask your overfed cat!). This has little to do with genes in most cases: those who are congenitally predisposed are mostly clear-cut, and there are such cases. Adult-onset diabetes often, but not always involves overweight, for reasons that are undoubtedly partly genetic, but also probably very variable from case to case.<br /><br />4. Even if your genotype affects your response to environments somewhat, each fat person is likely to have a different genotype (different variants at the many contributing genes). These can be correlated among close family members, even if they differ among families, or people from different populations. So predisposition can also be similar among family members.<br /><br />5. Your family has something to do with your traits because families share behavior, diet, attitudes, and so on, as well as genes.<br /><br />6. History shows, clearly I think, that if people did not overeat and had good activity levels, diabetes associated with weight (as opposed to the juvenile form of diabetes) would be much rarer. But some people would have gotten diabetes anyway: that is the subset that is truly, genetically predisposed. It does not seem to be a large number and it does seem to involve great heterogeneity in the genetic reasons for it. <br /> <br />7. Your children will have inherited genetic variation affecting all sorts of traits, including body shape, from both you and their father. Since only half of what you carry genetically is transmitted to any given child, and the same for their father, there is no simple prediction among relatives for this kind of trait. But most likely, if they don't get heavy, they won't get diabetes. However, these things are not simple, and not so highly predictable, generally--which is one of the problems being faced, and that we try to write about!Ken Weisshttps://www.blogger.com/profile/02049713123559138421noreply@blogger.comtag:blogger.com,1999:blog-1812431336777691886.post-2009729242705645012009-04-23T08:47:00.000-04:002009-04-23T08:47:00.000-04:00so, if my fat maternal uncle and my fat paternal g...so, if my fat maternal uncle and my fat paternal grandfather had diabetes, where does that leave me, genetically and environmentally? Is the risk greater for the fat part, or for the family genetics part? Would they not have gotten diabetes if they didn't get heavy? What about my children who are part black with their paternal grandmother, uncle and father having diabetes, and only the uncle being heavy?<br />Doesn't genetics play a part in the risk of getting that disease? And doesn't it interact with the environment, i.e. the amount and kind of food one eats and how much exercise one gets? Who's at greater risk - you or me?Jenniferhttps://www.blogger.com/profile/10781510687154219618noreply@blogger.com