One of the biggest issues with identifying cause (and many other topics around autism) is that we apply the term "autism" to a wide range of individuals. You have some who are incredibly high-functioning that qualify primarily due to their lack of social ability.
On the other end, you have some who are entirely non-verbal and often non-communicative in any form, entirely unable to care for themselves, and often have accompanying medical issues (gastro, immunity, etc.).
We call both autism, yet they are entirely different other than a few shared characteristics. Is it likely that both groups have the same cause?
I am not a biologist, but from the press (yeah, no anti vaccination sites in Germany!) it is
- Do the parents have autism?
- Is the father old?
- Is the mother old?
- Was the child born (very early)?
- Did the mother have certain illnesses during pragnency?
A lot of the talk lately has been linking older fathers to a rise in autism. The theory being that higher chance of mutations with sperm as you get older (and as you have been introduced to more radiation, carcinogens, etc).
The underlying causes of autism are still not well understood, and are likely multifactorial and complex. Autism is fundamentally a disruption of the brain's neurological processes. This can occur within the neurons themselves, at the neural synapses (connections between neurons), or at a more structural/neural organizational level. As has been pointed out elsewhere, the diversity of autism is very great and this is certainly recapitulated at even the most basic neurobiological levels. Despite the high prevalence of autism, the complexity and diversity of the disorder has made it hard to study autism in labs, in epidemiological settings, and in treatment settings.
Nonetheless, it's possible to break out the causes of autism into two main groups:
1. Genetics. Based on large twin studies and family studies, it is believe that the underlying between 50 and 80% of autism cases are due to a genetic mutation, set of genetic mutations or otherwise influenced by genetics. The advance of sequencing technology in the past five years has made possible to sequence the genes in the human genome across thousands individuals with autism and their families. This has given rise to the idea that "de novo" mutations, new mutations which arise in the child, are a primary cause of autism. Every newborn has a set of new mutations, which are mostly benign or inconsequential. However, a small fraction of new mutations are detrimental to the production of key molecules or proteins needed by neurons to function properly. Researchers have identified that perhaps 20-30% of cases of autism have a new mutation which could plausibly underly autism. However, these mutations are incredible diverse-- the same de novo mutation is seen more than once only very rarely, and the top 5-10 most commonly mutated genes account for only ~1% of autism. The long tail makes it necessary to sequence tens of thousands of individuals to pick up signal. A second set.
2. Environment. It's thought (but poorly understood) that certain environmental factors, especially during pregnancy, could also underly autism. Alcohol, for example, can cause Fetal Alcohol Syndrome which can present with autism-like features. Unfortunately, this half of the equation is not my subject expertise so I'll leave it at that.
As a note about searching for information: While google can be unreliable, Google Scholar (https://scholar.google.com/) can be quite helpful.
Interesting, wonder if Google's algorithm is even prepared to rank "there is no good answer" as a good result. I mean it's optimized to provide good answers, if there is no good answer perhaps the algorithm just breaks apart completely.
I mean, there has to be pages that say: there are no good answers (but we also can't say it's vaccines).
Also, I wonder why I'm being downvoted. Google meddling with search results is nothing new, sometimes they're even legally/politically forced to do so. Assuming we get unfiltered results is very naive.
Not to detract from your observation, but just as an aside, I wanted to mention that less than an hour after your comment, googling for "cow thiophenol romanesque establishment" (with or without quotes) lists this very page as the first result. Google must be indexing certain sites (like HN) very frequently.
Actually, it seems some site called "Hacker News" has a page on that stuff, but accessing it just led to a discussion about Autism in adults. Go figure...
A whole other issue is their bubble. Once you start clicking certain links etc, Google will take that history into account when sorting the results. Thus you get into a "positive" feedback loop...
I have a question that maybe you can help me with.
Why do people care that other people's children aren't vaccinated? If your children are vaccinated they're protected, period. Who cares about other people's children, especially if they have all sorts of unfounded ideas about vaccination? Why not live and let live? Why do people want to force other people to vaccinate their children? I never understood that but I'm sure I'm missing something hugely obvious.
I would vaccinate my children but I don't understand why I should also join some movement that is trying to force other people to do something they don't want.
Because it's not, "your children are vaccinated they're protected, period." The vaccines are not 100% effective, and an extremely small portion of the population shouldn't be vaccinated. For the sake of the people who aren't immune, it's best if the vast majority of people around them are immune.
> For the sake of the people who aren't immune, it's best if the vast majority of people around them are immune.
And what is the plan to go about that?
Just force-vaccinate these folks' children, something they vehemently oppose, thus traumatizing both parents and children in the process? What is the proposed plan to go about this in a way that is acceptable to both sides? Or is it the case that these anti-vaxxers shouldn't be respected and should have no rights just because they believe a fantasy? Because if that's going to be the new standard we'll have to have a giant conversation about gods.
Some amount of kids can't get vaccinated due to medical reasons, it's not safe for them.
And if less than 80% - 90% of the total population are unvaccinated, you get these large outbreaks like we're seeing today. At 95%, it's a lot harder for that happen.
Quite possibly as wide as the spectrum itself, a recent article i ran into talked about brainscans showing idiosyncratic across people on the spectrum, while "normal" people were more uniform.
