autistic Neanderthals?

[mellowtigger]

I've mentioned before my Neanderthal ancestry (and my curiously hairy ears), thanks to 23andMe genetic testing. Since that time, 23andMe has updated their findings, reporting me at <2% Neanderthal, but still my 268 variants they found (out of 7,462 tested) rates me at higher than 86% of their other customers.

Although I've mentioned the SPARK genetic database once before, apparently I've entirely neglected to mention that I've contributed to their database. After learning about their project during a local Minneapolis autism conference, I contributed saliva dna to their database back in 2016 April, as an adult with ASD. My non-ASD brother helpfully contributed too soon afterward. I didn't get the notice that "We have completed the genetic analysis of your saliva sample" until 2021 July.

I've written before that I suspect "autism represents a different (specifically, an older) form of human intellect." Now, there's some small evidence to add to that suspicion.

"It has been estimated that Eurasian-derived populations have approximately 2% Neanderthal DNA, which was acquired during introgression events occurring shortly after AMH migrated out of Africa [2, 3]. These hybridization events occurred somewhere between 47–65 thousand years ago (kya) [4]. A subset of Europeans later immigrated back into Africa approximately 20 kya, bringing some of this Neanderthal ancestry with them, such that all modern Africans have a small but measurable amount of Neanderthal DNA from the event [5].

Enrichment of Neanderthal DNA is also associated with enhanced neural connectivity within visual processing systems, particularly between the intraparietal sulcus (IPS) and the occipital cortex and fusiform gyrus, and decreased connectivity within the default mode (social) network [14, 16]. Importantly, many of these same connectivity patterns are recapitulated in autism, which is a major impetus for the current work.

In light of this evidence, in the current study we addressed whether Neanderthal DNA is enriched in autistic people and their siblings compared to ethnically-matched controls. We accessed whole exome sequencing (WES) for autistic probands and unaffected siblings from the Simons Foundation Powering Autism Research (SPARK) Database [21] for comparison against individuals in the Genotype-Tissue Expression (GTEx) and 1000 Genomes (1000G) databases [22, 23]. Significant enrichment in the autism group was especially driven by rare Neanderthal-derived variants, but also some common variants, which suggests weak but ongoing purifying selection towards removal of some of these single nucleotide polymorphisms (SNP) from the human genome.

- https://www.nature.com/articles/s41380-024-02593-7, "Enrichment of a subset of Neanderthal polymorphisms in autistic probands and siblings"

I'm glad to see that SPARK's genetic collection continues to produce interesting associations. I look forward to future links with early Harappa civilization, potentially an example of what an autism-dominant culture could be like.