Autism roots

Deepthought said:

So apologies again for the linguistic jumble and not providing the relative data at the time of posting ~ as I thought it was quite common knowledge when I posted. Sorry.

Not a linguistic jumble and no need to apologise. It's always interesting to know why other people have differing beliefs, and to trace back the reasoning and evidence.

I'm sure oxygen deprivation during or after birth can cause brain damage and learning disabilities, but my impression is that it's not seen as a prominent cause of either ASD or classic autism. The Wikipedia article seems to reflect the current balance of thinking, but to the first approximation the best answer I've heard to 'what causes autism?' is 'no one knows'. There is an 'emotional trauma' kind of theory, as I mention with Tustin, but I think that's psychoanalytic woo just trying to find a niche for itself; she herself also refers to a continuum with brain damage, it's just that conception from the 1970s or so hasn't been pursued, possibly because there's no single linking medical factor.

I didn't find much relevant on Science Daily except this from relatively recently, 2016:

https://www.sciencedaily.com/releases/2016/06/160607220116.htm

As it happens, I know that there was a theory of depression that sounds precisely the same, interaction of short variant* 5-HTTLPR X social stress. That theory had a brief period in the sun as a 'genetic cause of depression'. Then it magically turned out not to exist although social stress alone had an effect of course.

(I entertain the unpopular view that autistic characteristics or at least negative social outcomes of them could be acquired by social stress (what are my sources? Can I leave those for a rainy day?) It's taken me a while for me to really accept that human personalities and mental abilities differ. On the other hand, I also like the Spikins theory and I'm also influenced by a scholarly paper by Crespi, Autism As a Disorder of High Intelligence.)

(*) That Wikipedia article also mentions our old friend the amygdala. Not sure if that will cause Graham to come up with a Grand Theory of Autism, or he'll get completely lost in a maze of books and never emerge.

Cassandro said:

This is not the use of the word 'genetic' I would have expected, particularly given you otherwise exclude genetics from your list of causes (were those three items meant to be a complete list?). I don't see scientific evidence for this.

Please forgive the descriptive mess, as my linguistic networks are and have been massively fried of late ~ due to multiple daily seizures for the last few months, so its like roadworks, diversions and all that with the landscapes of my descriptive terms, sorry.

And yes womb trauma, birth trauma and environmental trauma are a complete list. With genetic predetermination from previous uterine / prenatal traumas in the genetic lineage being a large factor ~ but not necessarily causing autism unless triggered by one of the three traumatic instances.

Scientific evidence for which as above quoted (in my original post on this matter) and again below:

https://www.sciencedaily.com/search/?keyword=natel+and+perinatal+trauma+cases+autism#gsc.tab=0&gsc.q=natel%20and%20perinatal%20trauma%20cases%20autism&gsc.page=1

So apologies again for the linguistic jumble and not providing the relative data at the time of posting ~ as I thought it was quite common knowledge when I posted. Sorry.

This is a repost of a previous reply where the formatting was messed up.

Deepthought said:

Here's a few that I just quickly found (and there are many like it as it is not really all that new a thing really):

It's not a new thing. The first time I ever read a story about an autistic child was about 1980 in a copy of Readers' Digest (to which I found myself oddly relating). There was an implication there that hypoxia and exposure to cold at a few months old was somehow related to the change from a normal child to a nonverbal child. I'm not saying it's impossible, but there is a tendency for parents to lock on to any significant preceding event; hence the MMR myth became so popular.

Deepthought said:

https://pdfs.semanticscholar.org/5eb8/d1064d8510ea63376b1521e3e5c0af57d496.pdf

Juul-Dam et al, 2001.

The results of this study support previous findings suggesting that there is a consistent association of unfavorable events in pregnancy, delivery, and the neonatal phase and autism. However, the interpretation of these results is difficult, because the specific complications that carried the highest risk of autism represented various forms of pathologic processes with no apparent unifying feature. This lack of specificity may indicate that various types of physical damage may underlie some features of autistic symptomatology, but that no single complication or cluster of complications is responsible for the development of autism. Furthermore, this may indirectly support the hypothesis that autism has a genetic cause determining a particular pathologic development that may even cause these complications to occur.

Uterine bleeding was one thing picked out. However, they also found a statistically significant association with not smoking! They also didn't control for parental age, and there may have been a selection bias at work back in then concentrating only on 1 in 1000, mostly with autistic disorder/Kanner syndrome. I'm not sure which of the factors they mention have been supported since, but in all cases they of course apply to a minority of autistic people.

Deepthought said:

http://www.frances-tustin-autism.org/eng/pal_pdfs/MaielloPaper1997prize.pdf

This is subjective psychoanalytic speculation. Basically any thought or anecdote that goes through the writer's head is recorded, regardless of presence or otherwise of any logic and without critical testing.

I'm dismayed to see that there's a website devoted to Frances Tustin. It seems she only moved on from 'refrigerator mother' stuff because she was forced to. I have a book by her open at the moment, only because it's a good soporific. At one point she writes 'In reading the reports of the sessions, you may have felt that my remarks were less sane than those of the child.' Quite. For example, when an autistic child draws or even notices a cross, Tustin interprets it as a breást - concentric circles might make sense, but a cross? Psychoanalysis is pure woo.

Deepthought said:

http://pediatrics.aappublications.org/content/87/5/761.short

I don't have access to the full text.

Deepthought said:

2.) Genetic Trauma involves the baby experiencing a traumatic birth experience ~ umbilical around the next, stuck in the birth canal or forced deliveries involving forceps deliveries etc.

This is not the use of the word 'genetic' I would have expected, particularly given you otherwise exclude genetics from your list of causes (were those three items meant to be a complete list?). I don't see scientific evidence for this.

The Wikipedia page is more up-to-date, although as always you don't know what statements have been inserted by people with an agenda:

https://en.wikipedia.org/wiki/Causes_of_autism

The references to immune reactions seem genuine but weak evidence and the studies seem prompted by the MMR 'controversy'.

I agree with what Trogluddite says, and just want to add a bit.

There's space on these forums for all kinds of discussions, people looking for various types of help and various types of understanding. However, this forum or 'community' is not a way 'to make contact with the NAS', and you'll need to do that directly, although I understand it can be difficult. Most people here aren't even members of the NAS, just people who have been given a diagnosis of autism spectrum disorder, or who have a child or partner who has. Yes, the subject of this thread's not going to help you. You might get a better reception if you start your own.

So I'm not here to defend the NAS. However, I would point out that they are not the main reason for more and more people being diagnosed with autism. That is a trend that has been happening internationally for many years. As a result I have a diagnosis (ASD) that means I theoretically could be sectioned under the Mental Health Act without being mentally ill. Not all disabilities are visible.

So good luck in opposing the order against your son and getting him proper care. There are in fact quite a few verbal autistic people who are working with parents for the rights of autistic people who are currently detained or at risk of detention. Have you come across '7 days of action'? I don't have full details to hand, but they're mentioned here:
https://www.caremanagementmatters.co.uk/7-days-of-action-2017/
https://theatuscandal.wordpress.com/

I've posted some lists of possible sources of legal help:
https://www.autism.org.uk/directory/browse/cid=4~aid=1.aspx
https://www.disabilityrightsuk.org/getting-advice

Deepthought said:

Here's a few that I just quickly found (and there are many like it as it is not really all that new a thing really):

It's not a new thing. The first time I ever read a story about an autistic child was about 1980 in a copy of Readers' Digest (to which I found myself oddly relating). There was an implication there that hypoxia and exposure to cold at a few months old was somehow related to the change from a normal child to a nonverbal child. I'm not saying it's impossible, but there is a tendency for parents to lock on to any significant preceding event; hence the MMR myth became so popular.

Deepthought said:

pdfs.semanticscholar.org/.../quote]

Juul-Dam et al, 2001.

The results of this study support previous findings suggesting that there is a consistent association of unfavorable events in pregnancy, delivery, and the neonatal phase and autism. However, the interpretation of these results is difficult, because the specific complications that carried the highest risk of autism represented various forms of pathologic processes with no apparent unifying feature. This lack of specificity may indicate that various types of physical damage may underlie some features of autistic symptomatology, but that no single complication or cluster of complications is responsible for the development of autism. Furthermore, this may indirectly support the hypothesis that autism has a genetic cause determining a particular pathologic development that may even cause these complications to occur.

Uterine bleeding was one thing picked out. However, they also found a statistically significant association with not smoking! They also didn't control for parental age, and there may have been a selection bias at work back in then concentrating only on 1 in 1000, mostly with autistic disorder/Kanner syndrome. I'm not sure which of the factors they mention have been supported since, but in all cases they of course apply to a minority of autistic people.

Deepthought said:

www.frances-tustin-autism.org/.../quote]

This is subjective psychoanalytic speculation. Basically any thought or anecdote that goes through the writer's head is recorded, regardless of presence or otherwise of any logic and without critical testing.

I'm dismayed to see that there's a website devoted to Frances Tustin. It seems she only moved on from 'refrigerator mother' stuff because she was forced to. I have a book by her open at the moment, only because it's a good soporific. At one point she writes 'In reading the reports of the sessions, you may have felt that my remarks were less sane than those of the child.' Quite. For example, when an autistic child draws or even notices a cross, Tustin interprets it as a *** - concentric circles might make sense, but a cross? Psychoanalysis is pure woo.

Deepthought said:

pediatrics.aappublications.org/.../quote]

I don't have access to the full text.

Deepthought said:

2.) Genetic Trauma involves the baby experiencing a traumatic birth experience ~ umbilical around the next, stuck in the birth canal or forced deliveries involving forceps deliveries etc.

[/quote]

[/quote][/quote]

This is not the use of the word 'genetic' I would have expected, particularly given you otherwise exclude genetics from your list of causes (were those three items meant to be a complete list?). I don't see scientific evidence for this.

The Wikipedia page is more up-to-date, although as always you don't know what statements have been inserted by people with an agenda:

https://en.wikipedia.org/wiki/Causes_of_autism

The references to immune reactions seem genuine but weak evidence and the studies seem prompted by the MMR 'controversy'.

[/quote][/quote][/quote]

Handi-andis said:

Interesting theory, but where is the research that backs up such trauma root claims?

Here's a few that I just quickly found (and there are many like it as it is not really all that new a thing really):

https://pdfs.semanticscholar.org/5eb8/d1064d8510ea63376b1521e3e5c0af57d496.pdf

http://www.frances-tustin-autism.org/eng/pal_pdfs/MaielloPaper1997prize.pdf

http://pediatrics.aappublications.org/content/87/5/761.short

Interesting theory, but where is the research that backs up such trauma root claims? I’d also challenge the theory itself as it does explain why some families have a higher prevalence of autism nor why one identical twin may have Autism but the other doesn’t. 

Plastic said:

In the natural world, the fittest survive, the faulty die out.

In the natural world, it is the most befitting that in fact survive, as adapting to the means of their respective environments ~ Darwin. There is no faulty anything in evolution, only adaptation, and each adaptation enhances the whole, as being a singular spatial harmonic of infinite subatomic, atomic and alto-atomic energy fields ~ Physics and Quantum Physics. 

Plastic said:

The whole MMR thing is a red-herring - there was no such thing as MMR when I was a kid - yet here I am.

There are three causes of autism:

       1.) Uterine Trauma;

       2.) Genetic Trauma,

and

       3.) Environmental Trauma. 

1) Uterine Trauma involves a pregnant mother experiencing a shock to her system, that may be anything from minor to severe ~ a severe shock in known cases involve one mother falling down stairs and going into premature labour, and two others involve the mothers losing an older baby each due to the respective children getting infections and dying. All three cases of psychological and physiological trauma occurred at about the fifth and half month gestation stage, i.e, the second trimester.

2.) Genetic Trauma involves the baby experiencing a traumatic birth experience ~ umbilical around the next, stuck in the birth canal or forced deliveries involving forceps deliveries etc.

 3.) Environmental Trauma involves accidents and infections that are quite severe for the newborn baby involving near death ~ involving the first few months or years it seems.

Some children as pointed out on this thread do get adverse reactions to immunisation treatments, but these are relatively few in number, and productive countermeasures can be used within a limited time frame not exceeding preadolescence ~ as I understand it. One countermeasure is Gut-Flora treatment, as can resolve the damage for 3.ET-Autism, and as can alleviate the symptomologies of 1-UT- and 2-GT-Autism also. Early treatment is key, and later treatments are or can be helpful.

A minor or major trauma can result in greater or lesser autistic trait combinations depending upon the genetic constitution of the child in question. The basic factor that seems to link all types of autism is oxygen starvation that results from the mother or child  hyperventilating (rapid shallow breathing) whilst the freeze, flight and flight mechanism is engaging fully and completely, and remaining essentially on through life for the child.

And in turn you are being presumptuous in thinking that because some of us may have less severe difficulties than your son, and at times discuss topics other than the need for support for such people, that we have no sympathy for a person in your or your son's position. There is nothing in any of the posts in this thread to indicate that any of us would be anything other than shocked and dismayed by your description of how poorly the human rights are respected of those who are detained against their will for spurious reasons (I have witnessed some of it myself via friends who have been "sectioned".)

The shared label is maybe an accident of historical changes in the view taken by psychologists, and how we are diagnosed and categorised is certainly a legitimate subject for debate (a debate which we have often.) But implying that the autistic adults here should be dismissed as malingerers just because our traits do not match your preconceptions is both insulting and does nothing to further your cause, with which the majority of us would surely concur. Saying that person A's needs should be dismissed because person B's needs are greater is a divisive fallacy, regardless of what labels might be used.

Nothing is being taken away from you by other's desire to discuss the topic at hand, nor is there any intention that it influence the policies of the NAS or any other agency in any way. There is no obligation to participate in this thread nor to agree with the sentiments expressed. You are as free as any of us to start your own threads for the discussion of issues more pertinent to you and your son; if we can discuss those things without sniping at each other, you may find that you have more allies than you think.

So do we all pull together to seek the resources needed by each in proportion to their needs (as promised by the NHS charter since its inception), or do we bicker amongst ourselves about who deserves to be called "autistic"?

You are quiet presumptious. as I said I was being kind. As to my reasons to make contact with the NAS website a day or two ago, we as a family have been a NAS Life Member for over 30 years member . Quite frankly the NAS seems to have devolved from its original purpose, originally only about 1 person in 4000 with most GP's only seeing at best 1 autistic patient some none at all. Today I believe 1 person in 40 is described as being on the autistic spectrum.  Well the NAS has certainly raised the autistic Profile in the media..

We have a situation where society and the media ignore the truly autistic person who will need 24 hour care for a whole lifetime, and will eventually have to have to be cared for in a specialist care home, for which the NAS originally was the leader in this respect, and have participated in. But there being one case of institutional abuse by NAS employed carers. and the home was closed.

Did you know that to do so, your local authority will get a Deprivation of Liberty Order from the Court of Protection renewed each year, but for the lifetime of the detained.

Did you know when the detained handicapped autistic person who is not mentally ill, who has never done anything seriously wrong other than being frustrated by their inability to communicate, eventually dies.

The Coroners death certificate will record the death as being "Whilst in Sttate Detention". I find that appalling and so should every person associated with the NAS.

I am going to appose such an order soon to be made against my son. It is a complete breach of his Article 8 Human Rights.

I really need the NAS to fund a HR Barrister to support me as My son's Litigation Friend.

Think about that instead what siminian ancestor had sex with whatever he could catch. and whether it was a "Lucy" or in Africa, or as thought today a completely separate "Lucy" figure but evolving separately in Asia.before Africa.that you are unaware of.

Given Graham’s post I went and looked at some of your other posts. In one you talk about genetic pre-disposition to autism, but the talk about head injuries, particularly in womb, could cause them. Plus a few other things, that I would repeat, but I suspect we could all empathise and support you if only you’d be honest with us. According to your profile you are a retired civil engineer and according to your post on this threat you have a 35 year old extremely autistic son. So could it be that having worked all your life, fought for your son like a dutiful father you were looking forward to retirement but you still have to care for him, rather than he you, and that’s making you feel done? Might you be the one that’s looking for answers, as why else would you read this thread as a carer?  

I’m sorry but I am not sure how best to reply to you, given that this entire thread has been about exploring a number of intriguing possibilities as to the origins of Autism. Like everyone with Autism on here, I’ve had Autism since birth. If you read my post carefully I am not looking fir a cure, far from it as it makes me who I am. I also stated categorically that I was not reopening the MMR debacle. What was being discussed was the question as to whether there has to be a single cause for autism, or whether people could have some sort of genetic trigger that made them predisposed to developing autism. If one looks at identical twins for instance, it’s possible that one may have and one may not have Autism. Why is that? It raises some interesting possibilities and questions. Similarly, we think of ourselves as one human species but could there be several sub-species? It’s an interesting area that most people have been willing to consider, as why does there have to be a single cause of Autism?

As for your other extremely judgemental comments. Yes I do have Autism, but no I am not searching for why that is, as I know my mum had it. I am simply having a grown up scientific debate with likeminded people where any view put is preferably accompanied and backed by scientific evidence. The autism Spectrum Disorder is wide and varied, from as you say non-verbal to those that appear normal. So why lash out at someone on the spectrum? Do you know the harm that your venomous words could do to me, no you don’t, so why write with such vitriol? If this site is to about sharing ideas and thoughts then what is it about? Does every non-mainstream post risk polluting other autistics minds, despite mainstream can sometimes be wrong? It is only by people asking questions and theorising that humankind moves forward and develops. 

The only thing in your entirely unnecessary, unhelpful and hurtful post i am intrigued by one is your insistence on referring to Autism as a syndrome when it’s a developmental disorder and the majority of a time it’s referrred to as a disorder, including by the National Autism Society.

Please Andy, writing absolute.nonsence. - Autism is a syndrome, it is not al illness you cant Catch it, You can't Cure it.,

It is the absolute Media interest Piffle of the Musings of your mind that some susceptible people, such as people with autism ( Not autistics ) might pick up on..My son aged 35 has been severely  autistic from the day he was born. I have had to fight for him, since then. People with autism have a devastating  condition. That can vary from Not being able to comprehend any Language despite being able to read and Write it, but not understand what they have written or read, or to imagian they are the result of interbreeding of early homkinoids. We are all the result of whatever was in the world before that. Infact we are all the result of Space dust. and at that the mind is open to consider anything.

I have been as gentle as possible with your musings which is your perogative, you are entitled to believe anything.

You are presumed to be on the Spectrum, Because I believe you are searching for what caused your autism. In the manner my very severly autistic son teaches himself to read at the age of 7 putting his 11 year old Brother to shame,and to pull his socks up. while not understanding what a word of what he has read or communition is about, for instance an autistic person may not understand "to Pull up their socks.". My son has been known to watch Bart Simpson in Russian - He does not understand Russian , but he is word perfect in the Simpsons, simply because he has seen the same cartoon hundreds of times.- The same goes for Bugs Bunny, Dangermouse etc.

question 1:

Handi-andis said:

Does there have to be a single root cause for autism or could there be more than one mechanism?

question 2:

Handi-andis said:

Could there actually be two "human" species on the planet?

Well this seems a learned thread, or at least one looking at expert research. I have to admit I will often link to a paper without having studied it in detail as I don't really have the energy or specialist research literacy.

Graham's Nature link above, for example, I just skimmed enough for me to assimilate the idea of a 'Neanderthal genetic load', and to wonder if phrenology will return in trying to find links to personality. Here's something by G. Bradley Schaefer (from a lower-quality journal) that I found via Wikipedia, asking

is there an “ASD face”?

That paper is also relevant to question 1. I think despite some enthusiasms about pet theories and overarching frameworks, almost all researchers will admit there are many different things contributing to 'autism'.

Current understanding recognizes autism as having a strong genetic basis with a complex inheritance pattern. Strong genetic factors are involved. As with all human medical conditions, there is environmental modulation. There is clear etiologic and genetic heterogeneity. Literally hundreds of “autism genes” have been identified. Thus, from an etiologic standpoint, it would be better stated “the autisms” rather than “autism”. This understanding will be critical as the science of autism therapies moves forward. Using targeted therapies for specific identified causes of autism holds the promise of improved outcomes and reduced adverse events.

On the subject of 'environmental modulation', Mandy & Lai provide a good and comprehensive review of 'The role of the environment in the developmental psychopathology of autism spectrum condition', distinguishing environmental factors that may add to, or potentiate/multiply risks, and those that may just be associated with autism for some other reason (see mention of taking SSRIs in pregnancy).

Trogluddite mentions epigenetics, and one of the strongest links mentioned by Mandy & Lai is the link between lack of folic acid in pregnancy and 'autistic disorder' (that is, classic Kanner syndrome), and folic acid seems necessary for inter-generational epigenetic changes to happen properly.

If you take autism as meaning differences or difficulties in engaging socially, then it's hard to avoid the facts that (a) engaging socially is an extremely complex process requiring all kinds of different human faculties, cognitive, emotional and other; (b) society is also extremely complex; (c) the interaction of these two is likely to be complex as well. Any number of things could 'go wrong'. This is why I think the notion of a 'syndrome' is misleading. It's also important to realise that some gene variant might be beneficial in one environment, but in other circumstances contribute to 'autism'.

I answer question 2 with 'no'. There were Denisovians and hobbit men (H floresiensis) and all the rest interbreeding. However, I don't even think autistic people and typical people are different tribes let alone species (as in 'finding your tribe' and the title of Neurotribes). I think autistic people are spread throughout every other way H sapiens divides and tend to crop up randomly, and you can also think of autism in at least two other ways: (a) communities may well benefit from having one or more individuals who think differently, are interested in things and animals, or find new knowledge, despite being on the outskirts of that community; (b) some communities stratify in terms of social (not economic) success and some people, based on personal characteristics and luck, are going to find things much harder going than others.

I've mentioned spending time at Autscape and other autistic-dominated events, and actually they're noticeably non-tribal and accepting diversity. There are people who find shared interests, but communication between two autistic people can be fraught with differing needs. More to the point, although autistic–autistic conversation is in many ways more relaxed and interesting and probably functional than autistic–typical communication, there can be long periods of (not necessarily uncomfortable) silence, which does suggest to me that it's not as rich an interaction as between two 'typicals', however defined. Graham mentioned being in a room of people wanting to talk about video games, when presumably he'd prefer to discuss (or read) Marcel Proust.

On the other hand I'm not ruling out the Neanderthal theory as something associated with a particular direction contributing to autism instead of its diversity. That is, all kinds of difference may be seen as autistic or 'weird', but there may be a functional variation in a particular direction, such as hypersensitivity, detailed attention, connection to animals and physical processes more than social relations, when occurring together approaching a 'syndrome'. The guy who made the 'Aspie quiz' has speculated at length on the Neanderthal theory of autism (I don't understand all the statistical conclusions from his testing). Jared Diamond believed Neanderthals didn't have spoken language, and that might fit in again (not forgetting that some autistic people are very verbose). One implication this has for me is that if the divergence is traced to at most 1.8 million years ago, and the assimilation of Neanderthals about 35,000 years ago in particular explains some common traits, then relatively well-funded research accepting genetic analogues for autism in distantly-related mammals like mice seems even less likely to be useful.

Fair enough. I get the point about people with Alzheimers, I hadn't thought of that.

I don't think the vaccine theory is true. There have been many, many studies that tried to find an association between autism and vaccination, and each one is clear that vaccines don't cause autism.

Here's a general overview of the history of how this idea spread: https://www.webmd.com/brain/autism/do-vaccines-cause-autism#1 

Here's another scientific study that gave several reasons as to why the idea of vaccines causing autism by inducing autoimmune response is flawed: https://academic.oup.com/cid/article/48/4/456/284219

The Neanderthal and Homo sapiens idea is quite fun, but I don't think it's true that "autistics contain some other neanderthal DNA that makes them more neanderthal than human". Firstly, we would be able to see differences in appearance if that were true: a wider, barrel-shaped rib cage, a reduced chin, sloping forehead, and a large nose. Second, and probably a stronger argument, is that you've said Africans don't have Neanderthal DNA, but autism does exist in Africans. And at the moment, there is no indication that there’s anything different about the presentation of autism in Africa. 

OrinocoFlo said:

As for the idea that there are 2 species of humans, it's an interesting idea, perhaps supported by the fact that MRI scans of autistic and non autistic brains show noticeable differences in activity.

I agree with your statements about vaccines, caesarean, and genetics.

....but this is not logical at all

Pretty much any MRI scans of any two groups of humans (grouped by a certain trait) show differences in activity. Children and adults show differences in activity - are children and adults two different species? Even controlling for same age same and sex, those people who have Alzheimers show different neural activity compared to those that don't - are people with and without Alzheimers different species? 

If you have an fMRI while being happy vs being sad, you'll see differences in activity...

Therefore fMRI scans showing differences cannot be a support for 2 species of humans.

An interesting topic!

Firstly I would ask; is there a third possibility; that there are multiple autism phenotypes? Autism is currently defined pretty much by it's behavioural signs, but different internal experiences might produce the same observable signs. For example; some of us find eye contact hard because it creeps us out; others find it hard because it adds to sensory processing strain; others, because of difficulties with focusing their attention. However, all of these could be labelled as the diagnostic sign "poor eye-contact" (would this even be a diagnostic sign at all in a culture which frowns upon eye-contact? - e.g. Japan.) Similarly with social reciprocation; does the person struggle because of poor theory of mind; because of slow language processing; because of lack of focus; because they have no motivation to?

I read a lot of research papers about autism, and I find that many simply make assumptions about the inner causes of observed behaviour, and only correlate the behaviour itself with outcomes. We could see autism not as a specific condition, but a category of conditions in which the internal model of the world differs from what is typical to a degree which leads to the diagnostic behaviours; but this doesn't imply that the "different internal world", and the sensory, perceptual and cognitive differences which cause it, are comparable from one "sub-type" of autism to the next. That there is a lot of commonality in our difficulties dealing with the non-autistic world may not necessarily imply that we share anything in particular genetically; the very fact that we are different may be more important to outcomes than the exact way in which we are different at a biological level.

The fact that the genetics of autism seems complex is not surprising; there are very few genes which act alone, and very few which code for a single physical or psychological trait. Each gene is just a code for producing certain bio-chemicals, subject to the type of cell, it's location in the body, environmental factors etc. - it's the particular combination of those bio-chemicals, the way that they interact, and where they are found in the body which determine the end result. This is further complicated by the relatively new science of epigenetics, which has shown that heritable changes can happen without the DNA codes themselves being mutated.

Much of our DNA is inert, chemically "turned-off" by chemical markers; but various factors have been shown capable of enabling or disabling these chemical switches, and the changes can be inherited - this is the essence of epigenetics. There are even suggestions that our life experiences can have heritable epigenetic effects due to things like stress hormones changing the state of these switches. In effect, there may be non-autistic people who have a set of genes associated with autism, but who show no effects because those genes are disabled; this might be revealed in subsequent generations due to a chemical exposure which epigenetically enables those genes without having to change the DNA code itself. This has been suggested as a mechanism for the recently reported link between autism and exposure to the pesticide DDT, and implies that the OP's suggestion of auto-immune related autism is not so far fetched. Some of us might, in part, be autistic because ancestors several generations removed were exposed to something environmental which we have never been exposed to ourselves.

Autism being a sign that we are more "Neanderthal" is an interesting idea. I wouldn't go quite as far as that, as I believe that all humans are mongrels to a greater or lesser extent, but it's certainly possible to come up with a mechanism for it. The environmental conditions may well have been very different between the migrations which led to Neanderthal societies and those of later migrations, so there could well have been evolutionary pressures which led to different kinds of perception and cognition being more fit in an evolutionary sense. The traditional definition of a species is that its members can produce viable offspring, but cases where speciation has been observed happening have led biologists to question how well this represents the spread of diversity. There may not be an easy way to decide whether Neanderthals were a separate species, just an outlying variation of our own, or some kind of accidental biological compatibility. They have now been shown archaeologically to have been capable of much the same toolmaking and artwork as our own species when it was still very young, so we may have been much more psychologically and socially similar than the traditional "ogre in a cave" impression of Neanderthals would suggest. Whether African populations, who don't have the Neanderthal component, truly experience less autism is also a very tricky point to establish; differences in economic status, social attitudes and healthcare systems could easily mask the true extent of autism, just as many of us here would not have been thought autistic as little as a generation ago.

I don't think there's much hope of finding specific causes except for a few special cases, as there are so many confounding factors; there will likely just be combinations of risk factors which in most cases would not be totally reliable as markers. However, I don't think we'll get very far along that road until researchers look more behind the social effects of autism into the perceptual and cognitive differences which cause them; we need to know first whether there are different sub-categories of autism, and if so, what they are.

What is your hypothesis though, as you have given us a very interesting simmaly, but have not said where you think the mutations come from, particularly given the statistics that show its passed on through families rather than as single occurrences. The simmaly would also imply that it could be breed out of a population, but I do not see that that has ever occurred. What is interesting is those tribes that have had limited outside contact and have low or non-existent autism rates.

I said from the outset that the MMR thing itself was a red herring, however, an autoimmune reaction to any vaccination is something that happens on a day to day basis, in the same way as people can have an allergic reaction to food, it is the same biological mechanism. So that is scientific fact, that some people will have an autoimmune reaction to the MMR jab, in the same way they can to the flu jab, which is why I am now hypothyroidic, or any travel immunisation. The probability of a reaction is very low, but given that as laid out above aspergians are more likely to have certain autoimmune conditions, they what I am doing is postulating a hypothesis that autistics might have a predisposition to autoimmune reactions. There is a body of work out there that supports the hypothesis and it is an area that is being studied for instance https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5373490/ or https://www.ncbi.nlm.nih.gov/pubmed/29301665 remebering that RA is an autoimmune disorder.

As for the scientific basis of the neanderthal hypothesis, that again was based on scientific fact "Neanderthal Genome Project found that 2.5 percent of an average non-African human's genome is made up of Neanderthal DNA. The average modern African has no Neanderthal DNA. This information could support the interbreeding hypothesis because it suggests that Neanderthals and other species only bred once the other humans had moved out of Africa, into Eurasia, according to a 2012 paper published in the journal PLOS." (source https://www.livescience.com/28036-neanderthals-facts-about-our-extinct-human-relatives.html). So in that respect there is a potential basis and an area in which a minor gene dominance could trigger one from being more human to more Neanderthal. As you said yourself, your identifican brother is NT but you are Aspergerian, the only difference has to be a single mutation or perhaps something else caused it such as an autoimmune reaction. 

All I am doing is putting forward two hypothesis that do have some genuine scientific information behind them, in order to start a discussion that may or may not turn out to be interesting.