Autism just plain isn’t mercury poisoning. When can we move on?
Even some of the people who loudly promoted the mistaken idea that “autism is just a misdiagnosis for mercury poisoning” have backed off. But, the groups that promote autism as vaccine injury are packrats: once they’ve collected an idea, bad or not, they won’t ever let it completely go.
Some of you will be thinking, dang, another mercury post. I agree, there are a lot of good arguments against blogging about the mercury-autism connection any more. For one, it gives the idea press that it just doesn’t deserve.
I do think this is worth posting about, though. “This” is the expert report from Dr. Patricia Rodier, submitted to the Autism Omnibus Proceeding. In a single document, we now have an expert on both mercury toxicology and autism. Not faux experts, or worse, businesspeople and public relations people, but an actual, bone fide expert in both fields. I.e. we have a good document to give to people who are being snowed under by the misinformation campaign promoting autism as mercury poisoning.
When Patricia Rodier testified in the Autism Omnibus Proceeding, I was very impressed–and I blogged it right away. I remember at the time telling a friend that it was good to finally see someone officially debunking things like Sally Bernard et al.’s paper, Autism: a novel form of mercury poisoning. My friend pointed out that any college freshman in science (and most not in science) should be able to tear that “paper” apart.
Unfortunately, “should be able to tear the paper apart” isn’t enough. Many people don’t have the time and/or energy. So, many people still think that paper is valid. Let’s face it, that “paper” should have been retracted by the authors long ago, but they still soldier on with the “autism is mercury poisoning” message.
Dr. Rodier’s qualifications are quite good. Her summary is quite good:
As a research scientist who has studied both the toxic effects of methylmercury in animals and autism in children and animal models, I believe I am qualified to evaluate the scientific merit of the allegation.
She may be the only person in the world who has studied both mercury toxicity and autism.
What does she think? In a nutshell:
My conclusion is that the allegation has no scientific support and is highly improbable
Dr. Rodier notes that the comparison that autism and mercury poisoning appear similar isn’t even close.
In othcr words, because the symptoms of methylmercury poisoning
are not similar to those of autism, the authors have tried to construct a new, hypothetical kind of mercury poisoning from symptoms of toxicity of other mercury species and symptoms never reported for any kind of mercury exposure. The hypothesis is not based of facts; instead, the facts are being selected, manipulated, and shaped to fit the hypothesis. The hypothesis is then offered as evidence. But hypotheses are not evidence.
Ouch. Ouch, that is, if you are someone promoting autism-as-mercury-posinong.
Dr. Rodier can back up her words, as we discussed in the previous blog post. But, let’s say that again, Dr. Rodier uses research based facts, not manipulated hypotheses, to come to her conclusion.
I need to get a clean copy of that document, one that looks as good as the information it contains. That document needs to get into the hands of people being lured by the pseudo scientists promoting autism as mercury poisoning.
Thank you, Dr. Rodier for putting yourself on the line to testify. Thanks also to the HHS for allowing these reports to be made public.
Left Brain Right Brain 
Rodier also does not see ‘autism’ as a genetically transmitted disorder. She has done work on the association between exposure to anti-convulsant drugs and a later diagnosis of an ASD. Specifically prenatal exposure to valproate acid ( an anti-convulsant drug) is associated with both structural abnormalities in the developing brain that are similar to autism autopsy results and autistic behaviors. Rodier has recommended the use of valproate acid exposure in mice as a valid animal model for autism.
http://www.ncbi.nlm.nih.gov/pubmed/17137645?
http://pediatrics.aappublications.org/cgi/content/full/113/4/S1/1076
http://www.ncbi.nlm.nih.gov/pubmed/18985861?
This report makes a number of very important points.
First that autism doesn’t look like mercury poisoning and mercury poisoning doesn’t look like autism. They appear completely independent and unrelated.
Second, chemical agents are associated with autism-like symptoms, and exposure to those chemical agents must occur during a certain development period in utero. This demonstrates that autism cannot be solely genetic. If it were solely genetic, then chemical agents wouldn’t change the incidence.
Third, there are multiple chemical agents that are associated with autism-like symptoms. This implies a final common pathway by which these different chemical agents exert their effects.
Fourth, infections can cause autism-like symptoms. She mentions rubella. There have been animal studies where multiple viral infections in utero have caused neurological changes in adults. Effects can be produced solely by immune system stimulation, an “infection” is not necessary at all. That is injections of compounds that elicit an immune response can cause neurological symptoms in the absence of an infectious agent. This indicates that immune system stimulation all by itself can activate what ever final common pathways are involved in the neurodevelopment changes in utero that lead to autism-like symptoms.
Fifth, that all acute effects known to be associated with autism exert their effects during the first trimester in utero. (there are some non-acute effects such as observed in Romanian neglected children).
deadalus2u–
It’s worth pointing out that Dr. Rodier (and just about everyone) that there are environmental causes of autism (which may or may not also have genetics involved).
A clear sign that someone is trying to manipulate you is when they claim to be arguing against the people who claim autism is purely genetic. Dan Olmsted, David Kirby come readily to mind, but there are many others. Olmsted and Kirby are particularly egregious as they purport to be journalists.
rajensen088,
you make an unsupported assertion–one which is easily debunked.
“Rodier also does not see ‘autism’ as a genetically transmitted disorder. ”
Could you demonstrate the logic that led you to that conclusion?
It doesn’t take a whole lot of digging to find her webpage, which states,
http://www2.envmed.rochester.edu/envmed/tox/faculty/rodier.html
Sullivan, I wasn’t trying to discount the genetic component(s) of autism. There are not a small number of senior autism researchers who do think that autism is purely genetic. There are ASDs that are purely genetic (Rett syndrome for example), but the majority of cases are not obviously genetic in that there is no single or few genes involved.
The only conceivable prenatal tests (at the moment) depend on autism being purely genetic. If there are environmental causes of autism, a prenatal genetic scan won’t detect them.
My own view is that there are (primarily) two aspects to autism, the neuroanatomy and epigenetic programming which starts happening in the first trimester and continues until early childhood and adolescence after which it is pretty much immutable (although there is some plasticity).
The second aspect is chronic ongoing stuff. I think this is the mechanism for increased incidence in Rumanian orphans subjected to neglect. This chronic ongoing stuff can be changed. I think that is the change that was observed in Zimmerman’s fever paper.
deadlus2u–
I should have been more clear–I was pulling out something I saw in your post for emphasis.
Sullivan, I think we are on the same wavelength in that any unified concept of autism and ASDs has to fit with all the data and not just a subset of it. The people studying genetics can’t ignore the environmental effects and the people studying environmental effects can’t ignore the genetics, and neither of them can ignore the epigenetics even though there is no way to measure it right now.
That approach is how one does science. It is not how one represents a client in a legal case. It is not how one tries to scam gullible marks. It is unfortunate that funding agencies are more enamored with fads than with good science.
daedalus: “My own view is that there are (primarily) two aspects to autism, the neuroanatomy and epigenetic programming”
My view is that there are four components: genetics, immunology, structural changes i.e. in dendritic spines and immunogens or auto-immunogens which need to be included in a unified model
Autism is a property of a phenotype, not a genotype. Individuals with the same genotype (monozygous twins) can be discordant for ASDs and can have different “severities” (which is a term I don’t like as applied to ASDs). Monozygous twins are different because many of the details of development are not specified genetically, but occur in response to environmental stimuli (i.e. interactions with adjoining cells). Those stimuli interact with genetic stuff during development via pathways that are non-linear and coupled resulting in an outcome that is “chaotic” in a mathematical sense, i.e. not predictable in advance and extremely sensitive to initial conditions. Identical twins are not “identical” because they don’t experience “identical” environments as they develop. Very subtle differences will cause the development pathways to diverge, as in the “butterfly effect”. There is a gigantic amount of redundancy and resilience in development to produce a functional phenotype, but those phenotypes will not be identical.
I was including neuroanatomy and epigenetic programming as one thing (in my own thinking) because they are both related and not really separable from each other or independent. Cells have both a geometry and an epigenetic programming. The geometry of the cells in the brain (neuroanatomy) and the DNA expression profiles of the cells in the brain (epigenetic programming) both are only changeable over long time periods (if at all).
The second thing, the ongoing stuff (in my thinking) includes acute immunity stuff (but not the epigenetic programming as for example due to early immune system activation in utero). Some of that ongoing stuff (oxidative stress for example) is maintained by the epigenetic programming which makes it quite difficult to change. I see it as good regulation around a bad setpoint. To cause a change you have to change the setpoint, otherwise normal regulation will counteract any change you try to impose.
It is difficult conceptually to divide complex physiology into separate components because there is so much cross-talk between all of physiology. Mostly that cross-talk is not something that can be measured or regulated independently using current techniques.
Sullivan;
Everone, including Rodier, agrees that there are genetic forms of ‘Autism’. But they are all genetic mental retardation syndromes (Fragile X, Tuberous Sclerosis, Down’s Syndrome).
All of these genetic mental retardation syndromes have a minority subgroup who may also be diagnosed with an ASD.
It is debateable whether any of the conditions merit an ASD diagnosis since the underlying brain pathology itself would lead to the current vague and ambigous definition of autism ‘A qualititave impairment in social reciprocity’. Adult stroke victims are also seen, as a group, to be ‘socially impaired’.
Rodier is not a member of what even Rutter has decribed as ‘genetic evangelists’. That group includes David Geshwind of UCLA, Anthony Bailey of the Wellome Trust, Fred Volkmar of Yale and many others. Genome wide scans of highly selective families (two or more family members diagnosed with any ASD) have been published in the last decade.
Not one gene specific to autism has ever been identified, not one, even in families you would expect to have the most risk for an ASD. The candidate autism genes have all been found to occur in othere neurpsyhiatric disorders, including schizophrenia, developmental language disorders, ADHD, and the large group with developmental delay associated with rapid improvement and normal outcomes. This group had no diagnostic category to fit into until 1994 when Kanner’s highly specific and core defining feature ‘Pervasive lack of responsiveness to other people – autism’ coded in DSM-III was complety removed from all diagnostic schemes and replaced by the vague, ambigous and subjective ‘qualitative impairment in social reciprocity’.
Children with developmental delay had no diagnostic category to fit into until 1994 and now fit into the category of PDD/NOS.
Prior to 1994 epedemiological studies showed a stable prevelance of 4 – 6 per 10,000. Since the new criteria, autism rates have been very stable in studies published since 2000, 60 – 70 per 10,000, a ten fold increase all can be explained by diagnostic substitution.
Interestingly,the prevelance of Fragile X autism within all ASD categories has declined ten fold in the same period.
“Not one gene specific to autism has ever been identified, not one, even in families you would expect to have the most risk for an ASD. The candidate autism genes have all been found to occur in othere neurpsyhiatric disorders, including schizophrenia, developmental language disorders, ADHD, and the large group with developmental delay associated with rapid improvement and normal outcomes.”
You have repeatedly posted this sort of nonsense without indicating why any knowledgeable person should believe that there is a specific autism “gene”. That is entirely separate from the question of whether autism is largely a genetically-determined syndrome.
I fail to see the significance of RAJ’s observation (“not one gene specific to autism has ever been identified, not one.”) I say that because this is true of almost every human phenotype I can think of, e.g. homosexuality, left-handedness, short stature, giftedness, mental retardation, any personality type, etc.
I fail to see the significance of RAJ’s observation (“not one gene specific to autism has ever been identified, not one.”) I say that because this is true of almost every human phenotype I can think of, e.g. homosexuality, left-handedness, short stature, giftedness, mental retardation, any personality type, etc.
Sure there are. Trisomy 21 (Down’s Syndrome) Rhett’s Syndrome, Tuberous Sclerosis are all single gene mental retardation syndromes.
ASD has not identified any gene specific to autism and cannot be considered a genetic disorder. Genetic susceptabilty does not equate either to genetic transmission or genetic inevitability.
You could state that even HIV is genetically determined in a sub-group since AIDS researchers have identified a single gene, CCL3L1 and Lower Copy Numbers in this gene substantially increases the risk for infection after exposure to HIV-1
http://www.ncbi.nlm.nih.gov/pubmed/19287150?
The candidate genes for autism are non specific in that the associations are weak, occur in other developmental conditions and in the general population.
A perfect example is ‘head circumference’ thought to an autism characteristic. Researchers have identified a ‘specific gene,, PTEN associated with macrocephaly, but the risk for autism is less than the risk for mental retardation/development delay and the genetic variants of PTEN occur in 5% of the general population.
20% of ASD patients have macrocephaly ( large head size) but 20 % of the same group have microcephaly (small head size).
There is plenty of evidence that genetic influences operate in autism, but to date, no evidence of direct genetic transmission.
If there is, name one genetic variant that ’causes’ autism.
The research comminity has never been capable of disentangling the confounding variable of mental retardation and autistic type symptoms.
A year ago the Autism Genome Consortium published a study with the usual breathless headlines ‘New Autism Gene Discovered’. They found a handul of cases (less than 1% of thousands of children in the AGRE database, with an association of ‘autism X-linked neuroligin’ genes . All cases were mentally retarded children who also met diagnostic criteria for ‘ASD’. Two of the cases were mentally retarded sisters. This led to the neulogin theory of autism.
SHANK3 is also a neuroligin gene associated with autism in mentally retarded children with ‘ASD’.
Another group looked at SHANK3 mutations in a large sample of autisic children with normal or greater IQ. They found no evidence that SHANK3 is associated with autism in cases with normal intelligence.
http://www3.interscience.wiley.com/journal/117884763/abstract
So far, every genetic finding associated with autism are either mental retardation genes or genes associated with a childhood language disorder.
It is certainly puzzling why the genetic researchers in autism have generally failed to date to use the same genome scanning technology in large groups of autistic children without mental handicap which is the only reasonable strategy to seperate mental retardation and autism in genetic studies.
I don’t find that surprising at all, RAJ. I’m still trying to understand what point you’re trying to make. Researchers are incompetent? Phenotypes not specifically associated with known mutations are invalid phenotypes?
“It is certainly puzzling why the genetic researchers in autism have generally failed to date to use the same genome scanning technology in large groups of autistic children without mental handicap which is the only reasonable strategy to seperate mental retardation and autism in genetic studies.”
That would assume that people with autism and no intellectual disabilities are identical to people with autism who do have intellectual disability in everything except for the ID.
Bad assumption without some sort of data.
ASD’s are a broad spectrum of causes and presentations. There is no reason I can see to expect that the causes are identical for all those with and without intellectual disability. There is reason to expect that this would be valid in some cases. That evidence being the fact that MZ twins do not have the same presentation in all cases. But, that is not sufficient to make the broader claim that RAJ is attempting.
“I don’t find that surprising at all, RAJ. I’m still trying to understand what point you’re trying to make. Researchers are incompetent? Phenotypes not specifically associated with known mutations are invalid phenotypes”?
Genetic researchers have for two decades unsuccefully tried to match phenotype to genotype. The only associations they have made is with mental retardation and childhood communication disorders with or without secondary isolated autistic-type symptoms similar, but not the same as what what has been described as the broad autism phenotype. The genetic mental retardation syndromes do not observe the presence of the broad autism phenotype in relatives.
The researchers who even Rutter has described as ‘genetic evangelists’ are not incompent, they are ideologues. Much of the current concepts of autism being a gene-gene interaction disorder are based entirely on a single study “Autism as a Stongly Genetic Disorder: Evidence from a British Twin Study’ published by Bailey et al (1995). I am currently preparing a paper that will provide evidence that the this twin study that has been the most referenced paper published in the last 15 years is simply not a representative sample of twins in ASD. and what the geneticists have viewed as closing the case for any environmental influence in autism, was in fact the consequence of poorly design methodology
There are a number of other twin studies, e.g. Steffenburg et al. (1988), Folstein & Rutter (1977), Ritvo (1985), and Coeteur et al. (1996). In addition, there are a number of sibling studies.
That 100% concordance in MZ twins is not found is not surprising. I don’t believe there are any disorders considered genetic where the concordance of MZ twins is proven to be 100%.
Be that as it may, consider this. Are the people who think homosexuality is probably genetic also ‘ideologues’ and ‘genetic evangelists’?
Are the rest ‘environmental evangelists’?
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