A (Very Brief) Primer On Genetics And Behavioral/Emotional/Developmental Disorders

Wednesday, November 28th, 2012

This will be brief.

There continues to be loads of information on the role of genetics on behavioral/emotional/developmental disorders. This pace will continue. But the big picture for parents can be elusive. So here is a primer.

Some disorders  are “genetic” in the classic sense—meaning they primarily have a genetic foundation. They tend to be very rare and distinctive. Examples are Fragile-X syndrome, and Down syndrome.

That said, most disorders these days are assumed to be “complex”—meaning that they arise from a combination of risk factors, both genetic and non-genetic in origin. In many cases, there may not be “one” definitive etiology but rather a range of causes that can vary from kid to kid. For example, it is believed that some cases of autism are due to rare genetic mutations (some of which may be associated with paternal age). But this type of causation may only account for a small fraction of the cases in the population. There may be a number of genes (some suggest it could be in the hundreds) that convey some level of risk for autism. And for these cases, the environment can also be a potent influence, as evidenced by recent twin studies. That said, the actual environmental factors remain elusive.

This idea of “complex” causation probably applies to the vast majority of behavioral/emotional/developmental disorders. ADHD is believed to be highly heritable—but there are no genetic markers that distinguish normative levels of inattention and hyperactivity from problematic ones. And just because ADHD is heritable, that doesn’t mean that the environment doesn’t matter. Biological environments (such as prenatal exposures) may play a role. The psychosocial environment is also very important in terms of shaping how ADHD gets expressed. In the case of “complex” disorders, genetics is often described as influencing “what is,” but not “what can be”—which is another way of saying that psychosocial interventions can be powerful approaches for altering behaviors that are “genetic” in origin.

We’ve learned a lot about genetics over the past few decades. We will continue to learn even more. But the reality right now is that, with the exception of rare “genetic” disorders, there is still more unknown than known about the role that genes play in the evolution of behavioral/emotional/developmental disorders. What we do know, though, is that environment matters. So whether we are talking about autism or ADHD or conduct problems or other issues, a parent’s best line of action is to get reputable psychosocial interventions that have been shown to work. Remember, genetics is, more times than not, more about “what is” rather than “what can be.”

Lab Experiment via Shutterstock.com

Flu, Pregnancy, Autism: What To Make Of Exploratory Studies

Tuesday, November 13th, 2012

On the one hand, the recently published paper suggesting a link between flu in pregnancy and risk for autism is an important one. Researchers continue to look for clues for any of the multitude of risk factors that might contribute as partial causes of autism. There is certainly interest in the prenatal period and exposure to many potential influences. 

On the other hand, as a scientist and parent, I start to cringe when I see studies like this one getting translated into hyperbolic headlines. Why? Simply put, what we’ve really learned from this study is that we might want to try to further study the associations between flu, pregnancy, and autism. That’s it.

Now, that might seem like a puny contribution. It isn’t. But what you need to know is that all studies reported in scientific journals do not have the same goal. Some hone in precisely on a given topic and try to cement knowledge with rigorous hypotheses. Others, however, provide an initial clue that something should be looked at closer. That’s where we are at with the flu, pregnancy, and autism link.

You should think of this study as exploratory. Why? There are a number of reasons, and I’ll list just a few. First – the study relied entirely on mother’s recollections. This isn’t the optimal way of studying the association – not because moms (or anyone else) are unreliable, it’s just that the most precise way would be to use a number of methods (including prospective in-person assessment and reporting, medical records, etc) to record data that are not easy to catalogue. Second, the study looked at a whole bunch of potential factors in a very large sample. This means that the findings that come out as significant can be due to chance. While this is always the case in science, it’s especially so when there is a really big sample (simply because a large sample means very small results can reach statistical significance) and lots of potential associations are tested – and it’s the reason that science demands replication across a number of studies before we agree that a finding is established. Third, this point is reinforced by the finding itself – the risk increased from 1% to 2%. Any explanation in science is important, but when you look at the numbers this way it’s a bit more realistic (and sobering) than headlines that scream that the risk is doubled. Yes it was – from 1% to 2%. Think about the “margin of error” you heard about all through the recent presidential election with respect to polling – the same principle applies here. This difference could be a systematic result – or just chance. And right now the effect is rather modest. The bottom line is that more studies are needed to build on this to figure out exactly what is going on.

I’m a big fan of parents – and anyone who is interested – getting closer to science, especially new studies as they come out. But if we are going to support that, we need to explain more about the studies and what we think they mean, and don’t mean, right now. So here you go. Right now, it’s certainly the case that physicians and public health experts continue to suggest that pregnant women get vaccinated for the flu. If you are pregnant, talk to your doctor about that right now. Right now, extrapolating from these findings and trying to figure out if a child is diagnosed with autism because the mom got the flu when she was pregnant is not a productive exercise. Pointing a finger at a pregnant woman who is sick and saying that her unborn child will be diagnosed with autism is certainly not productive and would be misguided (not to mention hurtful). These exploratory studies are done to help guide future practices, not assign blame or create panic. They only provide a guide to future scientific projects that might shed more light and someday deliver more helpful guidelines for preventing autism.

Question marks via Shutterstock.com (because that’s the take-home message right now)

The New Autism Diagnostic Criteria: What Will Be The Impact?

Thursday, October 4th, 2012

The impact of the newly proposed diagnostic criteria for autism have been debated this year and the conversation continues with a new study published online in the American Journal of Psychiatry (you can read it here). The key issue has been the extent to which the new criteria will lead to fewer diagnoses of autism. Here’s a summary of where things stand right now. 

1) The new criteria lumps all disorders along the autism spectrum together under one diagnosis. This means, for example, that separate criteria for Asperger’s Syndrome would no longer be in place. Whenever diagnostic lumping takes place, the criteria become less specific, in order to take in a large range of symptoms. A result of this is that clinicians making diagnoses have to use even more professional insight and discretion to determine if a diagnosis is warranted because the criteria are more general than before.

2) To account for the wide range of symptom expression that can be observed within this broad autism spectrum, there will be a severity scale, ranging from mild to severe.

3) A key concern has been that the new diagnostic criteria will result in fewer diagnoses of autism in the future. Some have claimed that this effect will be profound. The study cited above suggests that less than 10% of current cases would no longer meet diagnostic criteria for autism.

Now this is where the fuzziness in the debate comes into play. Whenever a child is not diagnosed with a condition, then the availability of services gets reduced. Do these 10% of kids still need services? Will they get a diagnosis that will permit access to services? This is really the crux of the question. Furthermore, there are suggestions that this study was a “best-case scenario” because it focused on more clear-cut cases and used expert clinicians with lots of experience (see, for example, the New York Times report on this). The implication is that once the new diagnostic criteria are used out in the real world, with a range of clinicians in terms of experience, the number of cases that will not be diagnosed may be higher than the 10% reported in the study.

Earlier this year, I asked an experienced clinician – Dr. Gil Tippy – to offer his take on the matter. He suggested that the rates of autism will not be severely affected if experienced clinicians are doing the assessments. His greatest concern was that the use of the new severity criteria would substantially decrease the number of kids who could receive services for their condition. His argument was that insurance companies could deny coverage to those who were given a “lower” severity rating of mild impairment – even though that “mild impairment” requires intervention. You can read the entire blog post here if you are interested in the details.

So I think there are 2 take-home messages right now:

1) The rate of diagnosis will go down – but it’s not clear to what degree.

2) The impact of the severity criteria on the ability of families to secure coverage needs to be considered in more detail, as this could result in impediments to secure treatment.

If you read Dr. Tippy’s suggestions noted above, he offers advice on how to advocate to ensure that kids are not denied services in the future. This is especially important as early screening and early intervention continue to be the most effective strategies for accelerating the development of youth diagnosed with autism. To that end, it’s important that all parents know the early signs of autism that would indicate the need for early screening – if you haven’t seen it before, here is a prior blog post that lists 7 key early signs that should never be ignored.

Autism symbol via Shutterstock.com

Red-Hot Parenting Recap (Sept 2012): Play, DNA, And Sleep

Sunday, September 30th, 2012

Three big themes in the world of parenting stimulated discussion this past month. Here’s a recap of these along with links to posts that take them on. 

(1) The critical role of pretend play – long cherished in the academic literature and embedded in childhood education – was, to a degree, challenged by a somewhat provocative review paper. To some, it seemed like the article’s primary goal was to suggest that pretend play may be overrated as a promoter of cognitive development in general and creativity in particular, and hence should be reconsidered in a school’s curriculum. My take was a little different.  I thought the paper did a good job of highlighting the aspects of development that are positively influenced by pretend play – especially social skills – while suggesting that the cognitive aspects may in fact not be the primary benefit:

“Is Pretend Play Overrated?: The Take-Home Messages From The New Provocative Review”

The big thing for me was that, contrary to what you might have read about this paper, there was support for different types of play in the educational (and home) lives of young children (rather than suggesting to eliminate play). To wit, I also discussed a new study which revealed how drawing (particularly copying shapes) in toddlerhood predicts reading achievement in kindergarten even after accounting for traditional indicators of cognitive maturity:

Try This With Your Toddler: How A Particular Type of Drawing Is Associated With Reading Achievement In Kindergarten” 

(2) DNA was in the news in a number of ways. There was lots of interest in the recent link made between paternal age and risk for autism in offspring. Much was made of the idea that men, as well as women, have a biological clock. In response, I described what that may mean biologically, and how men (like women) may have to factor in rather inconclusive probabilities when making complex choices about having children at different ages:

Dads, DNA, And Choices

DNA and moms was also a hot topic. A study was characterized in the media as identifying “the mom gene” – implying that a woman either has, or hasn’t, a gene which would make her want to be a mom. I pointed out that genetics doesn’t typically work like this in humans, along with the, um, difficulties in making the jump from a study about female mice who had the function of a gene experimentally disabled to the human female:

Is There A Mom Gene?

(3) Sleep was also a big topic. While you may have read that a new study showed that it’s okay to let your baby “cry-it-out” the actual take-home messages were more fine-grained. In particular, the study was really about 2 types of sleep training methods, their utility in reducing infant sleep problems, and their lack of effects – positive or negative – 5 years later:

That “Cry-It-Out” Study: 5 Important Take-Home Messages You Should Know

I especially encourage you to check this out because we are finally seeing actual scientific studies on sleep training, rather than just debate. And the implications for parents are quite reasonable and, to my way of thinking, very important to know, given that all parents wrestle with figuring out how to get their babies to sleep.

Will The New DNA Encyclopedia ENCODE Change Our Understanding Of Childhood Disorders?

Thursday, September 27th, 2012

Virtually every developmental, behavioral, and emotional disorder is assumed to have a significant genetic component. Autism, ADHD, depression, anxiety, addiction, dyslexia – you name it, DNA is believed to play a role. For decades, genetic research has sought to uncover the specific genes that contribute risk to all these disorders. While progress has been made – including lots of hints that certain genes may play some role for some disorders – the overall state of the field is that there is much that still needs to be learned about genetics and childhood disorders. The latest hope is that a new understanding of how the human genome may be achieved by a deeper understanding of how DNA really works, as described in more than two dozen papers recently published.

The research initiative called ENCODE is focused on extensive regions in DNA that were thought to be, well, junk. You may have heard that only 20% of DNA is actually doing something. Well the new research is showing that nearly 80% of DNA is doing something, and what’s really important is not just the genes that code for proteins, but also the vast number of genes that act as switches that turn other genes on and off. This regulatory function has been known for a long time, and it’s importance has always been grasped. What’s different now is that it seems to be a predominant mechanism with many genes devoted to it. And researchers believe that it may hold clues to understanding how many disorders arise from expression of genetic risk factors.

What is really changing is the emerging idea that it’s not so much what is in the “core” genes that directly code for things,  but rather the complex mix of influences that turn genes on and off and hence influence development. Here’s where non-genetic influences – ranging from the prenatal environment to parenting strategies – may mechanistically link to how genes get expressed, or not.

You can anticipate sometime in the far, and probably near, future research studies that begin to explore this. There is certainly hope that embracing this increasing complexity of genetic systems will lead to more progress than we’ve seen in the past in terms of deliverables that either explain the causes of disorders or imply potential treatments. That, of course, remains to be seen, as we have heard lots of hype over the decades of how genetics will revolutionize our understanding of childhood disorders. We’ll need to take a wait and see approach to this – and continue to embrace interventions that are known to work right now for disorders, even without knowledge of genetic underpinnings. To that end, let’s hope that research portfolios continue to be diversified and not over-invest in genetic strategies that may, or may not, actually revolutionize treatment.

DNA and RNA via Shutterstock.com