Posts Tagged ‘ DNA ’

What DNA Can And Can’t Tell Us

Thursday, August 29th, 2013

The recent piece by Lisa Milbrand in Parents Perspective provides a fascinating glimpse into the modern world of DNA testing. In this post-genomic era, DNA may be thought of as something of a biological crystal ball. But it’s worth noting that the crystal ball may be quite blurry depending on what we are looking for.

Take for example rare diseases that are, in essence, genetic diseases. In this case, DNA tells us almost everything we need to know. If you have the gene variant that is responsible for the disease, you know that you will get the disease (although you won’t know exactly when). Such is the case for Huntington’s Disease along with many other single-gene diseases. That’s why babies can be screened for Cystic Fibrosis.

Other diseases are a little more blurry. If you carry a certain genetic variant you may be at high risk for disease but without perfect prediction. An example is the BRCA genes and breast cancer. These can carry risks along the lines of 85% (note not 100%) that you will develop breast cancer. Other genetic markers can operate in this probabilistic way.

But it’s worth remembering that most diseases – and in fact most human traits – are not due to the actions of a single gene. Multiple genes come into play, many (if not most) of which have not been identified. Multiple environmental factors come into play as well. Then of course there are the nearly infinite combinations of how genes and environments interact. That’s the stuff that makes the DNA crystal ball fuzzy indeed. The reality is that family history – rather than DNA testing – can probably tell you more about your (and your child’s) genetic risk for disease – and that the environment will be as telling. If you are wondering if your child will be very shy, or very outgoing, or somewhere in between, certainly their DNA holds some clues – but these aren’t easily revealed or understood. And they are the only determinants.

So if you consider DNA testing for yourself and your offspring, bear in mind what it can tell you, and what you want to know. Many times the answers just won’t be there.

Fortune Teller via Shutterstock .com

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Has The Economic Recession Led To Harsher Parenting?

Monday, August 12th, 2013

A new report from the Fragile Families and Child Wellbeing Study (FFS) suggests it has – at least for some moms.

This paper deserves consideration because it uses an informative base – a longitudinal study of nearly 5,000 families who have a child born between 1998 and 2000. By following these families from 2000 through the present, the researchers were able to examine how the economic recession led to overall changes in parenting – particularly harsh parenting. Here “harsh parenting” incorporates a range of behaviors like excessive yelling, hostility, and corporal punishment (which includes spanking and hitting).

The basic finding was that levels of harsh parenting by moms (dads were not included in this report) increased in relation to the decline in “macroeconomic conditions” – meaning the large scale economic factors that operated at a community level (and not just an individual level) were the trigger. The idea here is that pervasive economic stress causes parental stress, which in turn becomes family-wide stress. Prior elegant studies documented this during the Iowa Farm Crisis in the 1980s – such work included detailed observational studies that tested (and confirmed) such a family stress model that derives from economic decline. Essentially, when a parent is feeling the effects of uncontrollable stress, their patience with their kids goes down. Things that may not have typically bothered them now seem annoying or noxious. Harsh parenting is often associated with feeling frustration and lack of control. So here the point is that economic stress can end up having this kind of negative impact on moms, and ultimately their kids.

One of the interesting findings in the new paper from the FFS is that not every mom reacted with harsher parenting practices – rather it was moms who had a specific genetic predisposition to stress. What can we learn from this? Simply this – moms know themselves well. They don’t need a DNA test to know if they get stressed easily or tend to roll with things (even big things). So those moms who are highly reactive to stressors may especially want to consider that our economic climate might be influencing their parenting to a degree (even if there isn’t an immediate economic stressor per se). Talking to a primary care provider about stress management and perhaps screening for depression would be options to consider. Such intervention could offer a way to ward off the long chain of events by which economic recession impacts a child’s daily life. And, of course, let’s hope that insurance coverage permits such intervention – or else it becomes yet another trigger of economic stress rather than a way to ward off the effects of recession.

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4 New Things We’ve Learned About Autism Spectrum Disorder In The Last 2 Years

Friday, April 19th, 2013

As part of Autism Awareness Month, I’ve been reflecting on some of the new things we have learned about Autism Spectrum Disorder (ASD) over the past few years. Four findings stand out for me: 

It’s Not Just DNA: The landmark twin study published in 2011 suggests that while genes are important, environmental factors that increase likelihood of ASD are a key etiological influence as well. This finding is a critical one as it is the first twin study to show such a strong environmental effect after controlling for the role of genetics. It gives new impetus to examining a range of environmental influences in addition to searching for genes that increase risk for ASD.

Recovery From ASD Is Possible: While it’s been a controversial topic in the scientific literature, a recent study provides solid evidence that some kids can “outgrow” ASD. What we still don’t know is why that is the case. But this paper does stand out as important documentation that the phenomena of recovery is real.

Psychosocial Interventions Can Change Brain Functioning: While complete recovery from ASD is still rare, the positive effects of early intervention are not. New research published in 2012 provides dramatic evidence that some interventions – such as the Early Start Denver Model – may not just improve behavior, but also “normalize” brain functioning in response to social stimuli. This is a dramatic result because it demonstrates there is ‘plasticity’ in the brain that can be shaped by intensive intervention. It shows that we should give more weight to supporting psychosocial interventions, in part because they can effect biological development.

ASD Is More Common Than Ever: A recent paper reported that 1 in 50 kids have ASD. While it is difficult to generate a premise statistical estimate of the frequency of ASD,  it is clear that each new attempt reports that the frequency is higher than previously reported. This trend may, of course, reverse with the publication of the new DSM 5 criteria for ASD. That said, the newest estimates bring attention to how common ASD is in the population – and how many kids need appropriate diagnosis and intervention.

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Are There Mental Illness Genes?

Thursday, February 28th, 2013

For decades, researchers have tried to identify (with, as an overall statement, little success) the genes that contribute to a number of forms of mental illness. The idea has been to find genes that are specific to disorders. But a study suggests that some genes may predispose to a wide range of disorders.

Consider this new study which involved over 61,000 subjects. Four regions of the genome were found to increase risk for each of the following disorders: ADHD, autism, bipolar disorder, major depressive disorder, and schizophrenia.

Decades of family and twin studies have suggested that the genetic boundaries between forms of mental illness may not be as clear as the diagnostic categories we use. So it may not be entirely surprising that we are seeing “general” genes that may predispose to a wide range of forms of mental illness – many of which have overlapping characteristics.

To be sure, some specificity may reside in DNA that distinguishes schizophrenia from, say, ADHD. But we are at the beginning stages of sorting through the newer idea that there may also be regions of the genome that may offer either general protection against, or risk for, mental illness in general.

The etiological puzzle continues to get more complex, and more intriguing, the more we look into it. The prospect for more research to uncover interesting findings is strong. But given all this complexity, the prospect that it will lead to immediate improvements in therapeutics seems far in the distance (but then again, no one knows for sure).

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Childhood Psychiatric Disorders: Will Genetic Engineering Ever Be A Solution?

Wednesday, February 27th, 2013

Following a stimulating Intelligence Squared debate, we’ve been discussing genetic engineering (think of it as directly changing DNA) here at – both in terms of using it to create a “Super Baby” and to prevent disease. As a follow-up, let’s consider the likelihood of genetic engineering being a factor in the future for a number of childhood psychiatric disorders – or more to the point, the challenges that lay ahead. 

Autism Spectrum Disorder (ASD)

There would be hope that genetic engineering would be feasible in the future, as ASD is believed to be highly genetic in origin. However, the genetic basis for ASD is not clear. In fact, there may be a range of genetic etiologies. For example, some cases may be due to a rare genetic mutation – but there could be a number of mutations that can lead to ASD (not just one identified disease gene) making the idea of genetic engineering more challenging. The majority of ASD cases may reflect a complex mix of genetic and environmental influences – and the latest statistical modeling suggests that the genetic contribution to ASD may not be as strong as previously thought (and that the role of the environment may be more pronounced). For those situations, the idea of using genetic engineering is even more murky, because there may be many genes involved and they probably interact with a variety of environmental factors. All of this is not to say that genetics won’t lead to possible biological therapeutics – rather it’s to point out that the lure of genetic engineering as a solution may not be the avenue that will be pursued.


The best evidence to date suggests that ADHD is due to a mix of genetic factors along with the influence of a number of environmental factors. As discussed above, this makes the pure application of genetic engineering difficult to imagine. There may a large number of genes involved, each of which may only have a small effect on the likelihood of developing ADHD – which, simply put, would make it very difficult to know what genes to target. Again, it’s tough to predict where genetic research will go, but while it may certainly lead to improved treatments over time for ADHD, it’s tough to see the role of genetic engineering.


You’re starting to see a pattern here. Like ADHD, depression is also thought to be influenced by many genes as well as the environment. As discussed above, this constellation of risk factors does not suggest that genetic engineering will be a factor any time soon.

Conduct Disorder (CD)

This is the same deal as the case for ADHD and depression – and it may be that the environment plays an even stronger role in the etiology of CD.


The idea of genetic engineering is provocative. But the reality may be far in the future for most childhood psychiatric disorders – and in many cases it may not be the way in which genetic research gets translated into prevention and intervention.

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