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June 2006 Posts
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Minnesota Gene Pool Blog

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June 16, 2006

Family history and chronic diseases

I am keeping a rolling list of conditions that have family history as a risk factor. Today's additions include urinary incontinence in women and heartburn. Interesting.

Obesity and genomics: A Public Health Perspective

Obesity and overweight are at the root of several chronic diseases of public health significance. Diabetes, heart disease, hypertension, stroke and arthritis are just a few of conditions that count obesity as a significant risk factor. Trying to move our understanding of obesity beyond the obvious culprits of an environment that has an amazing abundance of easily accessible, calorie-rich and highly palatable food to the intrinsic factors that contribute to our desire for, consumption of and metabolism of our food is an area of active research. Genetics and genomics are helping scientists to better understand why some people seem to be more susceptible to obesity in this environment and why others aren't. Of course, the caveats is emphasized that genes are not deterministic for obesity or just about any other chronic disease, but they do tend to lean us in a particular direction. And if the environmental winds are going the same way, it is hard to resist.

The CDC's Office of Genomics and Disease Prevention and the CDC's Division of Nutrition and Physical have collaboratively published a webpage on genomics and obesity, seeking to look at it from a public health perspective. I include the link here for your review. Check it out. http://www.cdc.gov/genomics/training/perspectives/obesity.htm

June 15, 2006

Why do we do the things we do?

Why do we do the things we do? Is it because of our upbringing? Where we are in the birth order? The way we are treated in our relationships with our siblings or parents? How society categorizes us due to our sex, attractiveness, sexual orientation or racial background? How our religious traditions shape us? Do we do what we do because we observe other people in our sphere doing similar things? Or do we each have an inborn personality that merely unfolds as time passes and we pass through a pre-determined developmental process with doors opening and closing in orchestrated and predictable ways? Do we do what we do because of the innate strength (or weakness) of an intangible set of traits we collectively call "character"? Are some of us just more "good" or "evil" than our peers? Do we truly have free will? Are we completely responsible for all of our actions? Why do we do the things we do?

These questions have intrigued and vexed human beings ever since we made the leap from an animal conciousness to self-awareness. I wouldn't be surprised if this question has caused many of the members of our species more anxiety and angst than any other because we simply cannot find a complete and satisfactory understanding of either our own or others' behavior. It has been examined and approached from multiple perspectives, including religious, philosophical, humanistic, and psychological ones, all contributing their ideas, theories, observations, data and beliefs to the effort to understand, but the picture is never complete. And what is worse, these perspectives often conflict with or contradict each other to greater or lesser extents. Genetics has also weighed in on this question, attempting tease out what is intrinsic and what comes from the greater environment in which we develop. Using naturally occurring experiments in genetics such as studying how behaviors tend to run in families and how the behaviors of adoptees compare to their birth versus their adoptive families, we have tried to answer what aspects of our personalities and behaviors are inborn and which are not. These studies have suggested that at least part of behavior has genetic underpinnings, even while our ability to reason and choose, along with influences from our environment, are also variably influential in the actions we make.

With the completion of the Human Genome Project and the Haplotype Mapping Project, new tools are available to attempt to better define exactly what areas of the genome are associated with certain types of behaviors. These studies have focused on attempting to map regions across the human genome that contribute to behaviors and mental states that range from serious mental illnesses to tendencies to take risks, to believe in a higher being or to experience happiness. All of these studies challenge us for several reasons, not the least of which is the fact that a major underpinning of our social compact with each other is grounded in the premise that we have true choice in our actions and that we have the free will to exercise these choices. Suggesting that this may not be starkly true, or even true in the majority of cases, is challenging to us on many levels.

Amy Harmon in the New York Times has written a thought-provoking article that considers the contributions of genetics and environment to our behaviors and the choices we make. It is part of an ongoing series entitled The DNA Age: My Genes, Myself. In her thought provoking article, she discusses the tension that is caused by the intersection of the various conceptions of behavior as described by differing disciplines of study or thought. She also details some of the challenges that a growing genetic understanding of behavior will mount to the greater conception of behavior in our society. For examples, if our genes contribute greatly to what we do, should people be punished for these behaviors? Or, on the other hand, if some behaviors are largely intrinsic, does that make them immutable and resistant to change, suggesting that some people who violate the rules our society has codifed in law are more prone to rescidivism than others? Should this be true, what does our justice system do with this information? Do we treat these people differently? Do incarcerate them for their entire lives? Lots of hard questions and no easy answers, at least right now.

As another illustration, the genetic associations with the tendency to gain or lose weight are beginning to shape the perceptions of how we view overweight people in our society. Genetic underpinnings of our behavior may help to explain why some people tend to become overweight in our present environment of unprecedented plenty while other people seem blissfully immune to the multiple high-caloric temptations that plague their plump fellows many times aday. Ironically, it may be that at least some of us who battle the bulge on a chronic basis, along with the risk of the diseases associated with obesity, were the ones who were more likely to survive and reproduce in times past precisely because we could take advantage of sporadic opportunities to store away calories for the inevitable future when the times would not be so lush. The strategies that were so successful in eons past seem to have come back to bite a lot of us in the present day.

I am continuing to reflect on this subject because, obviously, it interests me. However, I will stop now and refer you to Ms. Harmon's article. She does a nice job of reviewing some of the issues, especially the ethical and social ones, that a growing understanding of how genetics contributes to behavior will challenge us with.

The Wild Streak? Maybe it runs in the family by Amy Harmon. The New York Times June 13, 2006 http://www.nytimes.com/2006/06/15/health/15gene.html?_r=1&oref=slogin

June 13, 2006

Heelstick test can cause unnecessary parental stress

The rapid expansion of newborn screening has been a blessing to many babies and their famiies who have had early detection and intervention for inborn errors of metabolism that are amenable to treatment and improved outcomes. For these families, the results are the fulfillment of all the promise of newborn screening.

However, there are almost always some costs or downsides to even the most beneficial program and newborn screening is no exception to this rule. Some of the costs of newborn screening are born by the families who receive presumptive positive or indeterminate results that may take weeks or longer to reconcile as either frankly positive or truly negative, that is, normal and may involve considerable contact with the medical care system. We in the business have tended to minimize this cost, suggesting that finding and saving lives and/or health of the kids with inborn errors is worth this cost. We have presumed (or hoped?) that families who go through the unsettling time when a diagnosis is not clear likely "get over it" once their child's health situation is resolved and found to be normal. These theoretical ramifications of false positives have been an unresolved issue for me for some time and I have wondered more than once whether there were any short and/or longterm consequences for the mental and psychological health of these families. So, it is with great interest that I noted this report by Waisbren and Gurien in the June 2006 issue of Pediatrics where the parents of babies who eventually were shown to not have a metabolic conditions were shown to have significant stress levels, even six months after testing. The authors suggest that this may be alleviated by better education of both parents and providers about newborn screening.

Money quote: "Although mothers in the false-positive group were interviewed at least six months after their child's diagnosis had been ruled out, they reported more worry about their child's future and rated themselves less healthy than mothers in the comparison group. Fifteen percent said their child needed extra parental care, versus 3 percent of mothers in the comparison group. After adjustment for socioeconomic factors, both mothers and fathers in the false-positive group had higher scores on the standardized Parenting Stress Index (PSI); 11 percent of mothers (versus no mothers in the comparison group) scored in the clinical range, in which treatment might be prescribed.

Waisbren and Gurian also found that false-positive tests affected the parent-child relationship: parents in the false-positive group scored more highly on two subscales of the PSI: a Parent-Child Dysfunctional Interaction scale and a Difficult Child scale. (The first asks parents to rate their agreement with statements like "I expected to have closer and warmer feelings for my child, and this bothers me"; the second has statements such as "My child makes more demands on me than most children.") "

This type of research is so important because we need to take into account these costs and work to address them. It is not fair that parents of kids who turn out to be healthy should be harmed in any way as a consequence of a program that exists to assure the health and wellbeing of all newborns and their families. By better understanding these unintended and unwelcome consequences, we can work to address and prevent them to the benefit of all.

A summary article can be accessed at: http://www.news-medical.net/?id=18240

Access to the article's abstract can be found via PubMed at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=
Abstract&list_uids=16740831&query_hl=2&itool=pubmed_docsum


Precise cite: Gurian EA, et al. Expanded newborn screening for biochemical disorders: the effect of a false-positive result. Pediatrics 2006 Jun;117(6):1915-21

June 12, 2006

Family health history and primary prevention

For those of you who are versed in some of the more universal parlance of the public health set, the term "primary prevention" denotes a familiar concept. Primary prevention is all about preventing bad outcomes for people, to maintain or improve health and to anticipate and head off problems before they become manifest in people's lives. Here, we are trying to use the concept of family health history as another tool for keeping people well by informing them of their risk for chronic diseases.

Family health history is an independent risk factor for several conditions that contribute greatly to the morbidity and mortality of lots of people. Examples of conditions that can run in families include many types of cancer, including the biggies of breast, colorectal, and prostate cancers. There are also families in which other cancers can be very prevalent. For example, our former President, Jimmy Carter, has a remarkable family history of pancreatic cancer. He lost at least a couple of siblings and one parent to this disease. Thankfully for him (and for us), he has so far been spared from this disease.

Other conditions that tend to run in families include cardiovascular disease, hypertension and stroke and diabetes. Interestingly, we often talk about obesity as being a very potent risk factor for both cardiovascular disease and diabetes. Having a family history of these conditions--especially if the relatives are closely related--is comparable with obesity as a risk factor.

So, if your relatives have all keeled over from chronic diseases, does that mean that you are doomed to their fate? The really good news is that if your relatives have suffered from chronic diseases like cancer or diabetes, you can use your relative's experiences of poor health as a cautionary tale and avoid a similar fate. There is almost always something you can do to allay or greatly reduce your chances of repeating their history. It isn't just about genes, in most cases, but rather about an interaction between environmental and behavioral factors with a susceptible genetic makeup. In other words, there may be some genes that are necessary for disease to occur, but they certainly are not the whole story by any means. Remove any one of the predisposing elements and health is maintained, even if there is a considerable genetic predisposition. So, even though you can't change your genes, you can change your behaviors and your environment (including diet) and stay healthy. For most of us, the family health history of common chronic diseases that we have observed in our parents, grandparents, aunts and uncles, can be averted by following some pretty basic changes in habits and environments. So, if you can, raise of toast to the health (or lack thereof) to your relatives. By learning from what health conditions affected them, you can up your chances to have a long and happy life!


June 11, 2006

Newborn screening and informed consent

The Minnesota Republican Party has added a plank to their party platform that would require parents to "opt in" to having newborn bloodspot screening for their newborn babies. This would be a major change from the current situation in Minnesota. Currently, parents can "opt out" of the program, but this very rarely happens. If the program is changed so that parents have to "opt in" to have their child screened, it is unclear what this would mean for the rates of participation. The concern is that many more kids would not be screened and that, sooner or later, a child with a treatable condition would be missed, resulting in permanent disability or death to the child. Also, if "opt in" becomes the standard, there will be a whole new informed consent process that will have to planned, developed and put into practice. Who would do this and what it would cost is unclear at this point. We will be watching this with great interest. Fee free to comment if you have any information or if you have perspectives on this.