Nature: Autism is almost 60 percent genetic

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A recent study published in Nature Genetics established that close to 60 percent of autism risk can be explained by genetic factors.

This is perhaps the most precise study on the heritability of autism so far.

From the abstract:

(My emphasis added)

Trent Gaugler, Lambertus Klei, Stephan J Sanders, Corneliu A Bodea, Arthur P Goldberg, Ann B Lee, Milind Mahajan, Dina Manaa, Yudi Pawitan, Jennifer Reichert, Stephan Ripke, Sven Sandin, Pamela Sklar, Oscar Svantesson, Abraham Reichenberg, Christina M Hultman, Bernie Devlin, Kathryn Roeder, Joseph D Buxbaum. Most genetic risk for autism resides with common variation. Nature Genetics, 2014

http://www.nature.com/ng/journal/vaop/n ... .3039.html

Here is a graphical representation of the findings and how they add up to the almost 60 percent genetic component of autism. The 52.4 percent mentioned in the abstract is the sum of the directly heritable (additive) components, while the remaining smaller genetic components are due to non-additive genetic effects (4 percent) and spontaneous mutation (3 percent).



And here is a press release quoting one of the lead authors with further explanation of the study methodology:
http://www.mountsinai.org/about-us/news ... for-autism

Last edited by GGPViper on 23 Jul 2014, 2:30 pm, edited 1 time in total.

Common variation makes the most sense for autism spectrum.
Only small percentage of "autism" is caused by inherited single-gene mutations like Fragile X or Rett or de novo mutations not found in parents.
Most autism is probably caused by combination of common variants also found in non-autistic people.

I noticed they only accounted for narrow-sense heritability... That's the easiest to find, but there's more to it, because the combination of the parents' genes can be more than additive, with Dad's 1 and Mom's 1 adding up to 5 instead of 2. (Consider those numbers to be abstract "autism levels", if you like, and set the "diagnosable autism" threshold at 3...)

Anyways, it's not really news, but it does quantify some of what we know already. It's a very conservative estimate of autism heritability, but it's still stronger heritability than any other non-single-factor developmental disorder.

This makes the most sense of any of the research I've seen to date- thank you for the posting. Helps to explain why autism has popped up here and there in my family tree but 'seemingly' at random.

Disappointed that alien abduction didn't make it into the findings.

You silly person!

You know, some people actually believe that, though. Along with other really odd things like crystal children or government plots to contaminate the atmosphere or fairy changelings or... who knows, I don't keep up with the way-out-there wacky stuff. (The minorly wacky theories, like vaccinations or "next step in evolution", I unfortunately have to keep up with because sensible people are sometimes lured into believing them and I have to know exactly why it doesn't make sense. But once they get to the point of believing that autism is caused by alien abduction, no amount of logical argument on my part is gonna help them.)

These results also seem consistent with imaging studies:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3812662/

I'm pretty sure it's "Indigo Children".
I was just thinking that a legit link to aliens would save a ton of money by not having to research all those other causes.

Besides, when you start asking specific questions like exactly what is going on there that makes subtle changes in the DNA code for no obvious reason, then you might as well just say "demons" and move on to the next issue.
Saying it's genetic isn't very much of an explanation.

I think it would do more good overall to put the research effort into better understanding how the DNA molecule functions in a larger sense.

This seems like an anti-rational, anti-science position. No one is just saying "it's genetic." You find out what causes subtle changes like methylation and single nucleotide changes (and not so subtle changes like copy number variations in which huge sequences of thousands, tens of thousands or hundreds of thousands of bases are duplicated or deleted) precisely by asking "what is going on here" and looking harder when there appears to be "no obvious reason." DNA itself wasn't obvious at a certain time.

There isn't one research effort that either gets put into this place or that place. Research into what genetic factors are associated with variations in risk of autism does not detract from or redirect fund from research into other areas of [micro-del, thanks Walrus] molecular biology including the overall functioning of DNA. The only place where there is anything like a zero sum game in this is in NIH grant funding--but then you are leaving molecular biology and entering politics. There you can throw up your hands and say demons did it, if you like.

This is one of the most active areas of investigation in science today. Physics may have big machines like the LHC, but advances in molecular biology and genetics is accelerating even faster than advances in computing power.

And it's easier than ever before for anyone interested to delve into this subject:
http://geneed.nlm.nih.gov
http://learn.genetics.utah.edu
http://www.dnaftb.org
http://www.nature.com/scitable
http://www.genome.gov/10000464

Last edited by Adamantium on 25 Jul 2014, 6:55 am, edited 1 time in total.

Just FYI, "microbiology" is the study of micro-organisms. This is closer to molecular biology.

Sometimes mutations are caused for a reason though, such as pollutants or radiation. I think knowing about those things has a purpose, and even discovering the causes of idiopathic mutations is a worthwhile activity simply for the pursuit of knowledge. We could easily have said that inheritance was "demons", but we didn't, and now we know all about genetics and DNA and protein synthesis... who knows what areas of science we could discover if we investigated mutations further?

Saying "it's genetic" is a big step on the road to discovering what it actually is. It's definitely better than the pseudoscience explanations which have been used to harm autistic and non-autistic children alike, and guilt-trip parents.

Out of interest, how qualified are you in this field? It seems to me that we know quite a lot about how DNA functions, though there's still more to be discovered in some of the details, but if you have a PhD in genetics or something and know that there are huge swathes of ignorance then I will bow to your knowledge. Regardless, the amount of funding spent on molecular biology dwarves spending on autism.

Yes. Comes of posting while working on a project in the wee hours of the night! Thanks!

While we're at it:

Now the autism researchers have to cross the desolation of Smaug and reclaim their ancient halls before they can get funding for a new GWAS...

Being a neurological condition that exist from the birth, I was expecting to be 100% genetic (or perhaps 90% genetic and 10% cause by diseases during pregnancy, brain damege during the birth and some other special cases)

I run into this situation a lot.
First I want to point out that sarcasm was intended to be in my post.
I thought the reference to aliens would have ensured that to be taken.
I was trying to joke about the alien thing.

The second part is that there is a very real and very significant divide between how our mental models work and how the physical world works.
Most of what we know in science is contained within the descriptions of our models.
No matter how many layers of descriptions you put on something, you always reach a point where energy is interacting with matter due to a systems intelligence, and since our instruments cannot detect energy directly, we are still left with a mystery about what exactly is going on there.

Genetics is not my specialty. I do know that the DNA molecule is a flexible crystalline structure made up of a great number of crystalline sub-structures, with both pentagonal and hexagonal sub-structures that link electrically forming an angle of 36* of rotation. That's ten base pairs per rotation in the crystal.

In genetics, the significance is generally considered to be more in the coding of protein bases than in the overall structure itself. It is also generally thought that shape of the substructures is intimately linked to the ability of other proteins to read and translate the coded information. That is their shape determines the most likely possibilities for chemical bonds that may ensue by the presence of that molecule.

The whole situation is often called self-organizing system intelligence. This isn't the same as a bowl filled with a mix of proteins interacting more or less randomly. In both situations there is energy interacting with matter, generally based on the nature of the energy and the direction of energy flow. The difference is that one set of interactions accomplishes anti-entropy and forms self-sustaining patterns. This aspect of energy/mass interaction is more specifically where my own interest is.
______________

The current thing I'm studying could very well be applied to genetics, though it is applicable to most scientific areas.
That is the problem of "How does nature make an angle?"

For example, two of the bases in DNA form a pentagonal shaped structure.

We have a pentagon. Pentagons contain 540* and have angles of 108* inside and 72* outside.
If the angle of the pentagon is shifted by 50%, then the outside angle becomes 36* which is rather common in nature and is present in the DNA molecule.

How does nature make a pentagon? First it must make an angle.
It is generally accepted that chemical structures are representations of electrical forces involved. Perhaps the question is how does electricity form a 72/108* angular relationship between masses?

How? Why? and Why does it repeat 4 or 5 times to make a pentagon?
Is it really even a pentagon or just multiple iterations of equilateral triangles?
Does the flow of energy stop once the structure is formed or does it continually loop perpetually?
What can disrupt this flow? What can protect the integrity of this flow?
Is there also a relationship with gravity or magnetic fields?

Perhaps you can see what I'm getting at.
To say that x-radiation or x-chemical can cause mutations is not something I consider a complete explanation. We're not even sure what keeps the structure in perfect order.
Calling it electrical forces is functionally little better than calling it demons.

I think it's great that the protein coding is being tracked and correlated with conditions. I'm not saying that should stop. I'm just saying that more basic understanding should be even more valuable.

Feel free to help me tackle some of these questions about energy flow leaving an apparent trail of angles in the material world.
If you want to consider these questions in regard to DNA, then consider that DNA shows very much evidence of having system intelligence imparted to it via binary logic gates.

DNA is a double helix structure overall
DNA contains base pairs
DNA replicates itself in a one-to-two fashion, and never in threes or fours.
Collective sets are grouped into twos. (pairs of genes)

Naturally electricity picks a path of least resistance which represents a binary decision, but that's really not an explanation at all. Least resistance could easily form a path of randomness or entropy, and nothing like a self-organizing pattern.

Sorry for getting off track. It's just my special interest lol.
Also, don't take it as me downing genetics, - or aliens.