autism and race - how common is it across the different groups out there

I am sure you have made a thorough job of researching the available statistics Iain. I suspect that at best the figures will give only a hint of the extent of autism, but as you say autism seems to affect varied cultures.  I am not knowledgeable in the field of statistics or autism, but I can’t accept that the figures would have taken into full account the extent of the problem of accurate diagnosis and the variables around criteria, gender, masking, educational background, culture, religion, economic situation, mental health …. etc. Moreover, existing studies seem to be small, or else aren’t accessible to the public. Where I live, parents of school age children are struggling to get their children assessed and some young people in the 18 - 25  age bracket are being referred only now. In this day and age, how have these young people gone through school and been missed or prevented from receiving a diagnosis. I have recently become interested in genomics and have learned that those of us not of African origin have between 1% and 3% genetic material derived from Neanderthals because Sapiens and Neanderthals interbred. The ancestors of today’s Asians interbred with Denisovan’s and those living in Papua New Guinea carry between 3.5% and 5% Denisovan genetic material. The Tibetans’ ability to live in extreme conditions at high altitudes is due to their Denisovan ancestors and the first Europeans were better able to cope with viruses such as the cold, and other pathogens, thanks to Neanderthal DNA. I cannot find any research looking at a possible connection between genetic origins and autism, but it is a fascinating and fast moving subject.

I am sure you have made a thorough job of researching the available statistics Iain. I suspect that at best the figures will give only a hint of the extent of autism, but as you say autism seems to affect varied cultures.  I am not knowledgeable in the field of statistics or autism, but I can’t accept that the figures would have taken into full account the extent of the problem of accurate diagnosis and the variables around criteria, gender, masking, educational background, culture, religion, economic situation, mental health …. etc. Moreover, existing studies seem to be small, or else aren’t accessible to the public. Where I live, parents of school age children are struggling to get their children assessed and some young people in the 18 - 25  age bracket are being referred only now. In this day and age, how have these young people gone through school and been missed or prevented from receiving a diagnosis. I have recently become interested in genomics and have learned that those of us not of African origin have between 1% and 3% genetic material derived from Neanderthals because Sapiens and Neanderthals interbred. The ancestors of today’s Asians interbred with Denisovan’s and those living in Papua New Guinea carry between 3.5% and 5% Denisovan genetic material. The Tibetans’ ability to live in extreme conditions at high altitudes is due to their Denisovan ancestors and the first Europeans were better able to cope with viruses such as the cold, and other pathogens, thanks to Neanderthal DNA. I cannot find any research looking at a possible connection between genetic origins and autism, but it is a fascinating and fast moving subject.

If you look at sub-Saharan Africa there is more genetic diversity and more relict DNA from other earlier human species.

I don't think ASC is confined to one genetic grouping, I think it's a basic human trait.

Have a look at Gina Rippon's book, The Gendered Brain, to get some idea of how small the samples used in many of these studies really is and the massive conclusions they come to from such a minute sample size.