the mellow tigger's musings

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.

First, don't panic. Even though COVID-19 is now epidemic across the USA and pandemic globally, it's still not an appropriate time to panic. The fatality rate is sufficiently high for healthy people to be concerned, even to be very concerned if they know people in high risk groups... but not panic.

Second, some definitions. We'll need these terms so we can discuss appropriate responses later.

• SARS-CoV-2 is the name of the virus.
• COVID-19 is the name of the resulting disease.
• Endemic disease is the constant presence of a disease in an area.
• Epidemic disease is the sudden increase of a particular disease over its usual endemic levels.
• Pandemic disease is an epidemic that has spread over several countries or continents.

Third, don't buy surgical masks. A surgical mask is not a respirator. Just look at the name of it to understand it. A surgeon dons the mask to prevent spread of disease from surgeon to patient, where the surgeon is the one hosting pathogens potentially harmful to the patient. These masks are effective at preventing someone who is already sick from coughing, sneezing, or simply breathing and spreading wet droplets of infectious material into their surroundings. The droplets must be wet in order to "catch" in the flimsy paper mask. The protection doesn't work nearly as effectively in the opposite direction for such microscopic particles. (It's more than zero, so feel free to indulge your paranoia only if market supplies are plentiful.) If dried infectious material is floating through the air in your vicinity, that paper mask is not effective in blocking them as you inhale. Don't buy surgical masks if you're healthy. Leave that stock on the shelf for people who are sick. That surgical mask might help slightly with large airborn material (when you're cutting drywall, or if the local volcano is spewing ash) if proper equipment isn't available, but don't use it for dried microscopic infectious particles. Sick people need those surgical masks.

Fourth, inform yourself. Thanks to the information age, there are many great opportunities in this category.

• RoyLab Stats on YouTube for current coronavirus numbers by country. This livestream has aired continuously since 2020 Jan 29, and I visit it occasionally.
• NextStrain for genome tracking. Basically, you get to watch evolution in real time from this open-source project. I recommend the "Situation Report 2020-03-05". Use the big arrow (bottom left of screen) to navigate pages. Watch on fullscreen computer, not smartphone. It's a lot of data to display.
• nCov Control for learning about how interventions can influence the trajectory of an epidemic. It's developed by people at University of Toronto.
• Dr. Mike Varshavski plays Plague Inc game on YouTube. This doctor, beginning a career of fighting disease, becomes hilariously inspired in a matter of minutes to grow a plague that wipes out humanity. It sounds dark, but I found these 11 minutes to be quite amusing. You also learn (which is the whole point of the game) important concepts of pathogen evolution and human sociopolitical investment.
• Dr. Mike Hansen describes autopsy reports on COVID-19.  These 10 minutes are maybe the serious version of the game video.  It's definitely "dark" material but also very enlightening about medical process, virus evolution, and human patient behavior.
• COVID-19 comparison to other diseases like flu.  (Edit: 2020 March 13 Fri.  I just found this link, and it has good information.)
• fact-checking at Snopes. (Edit: 2020 March 13 Fri.  Another new link.  It's also important to rid yourself of misinformation.)

I realize this post is more about what NOT to do rather than what to actively DO. I'll get to that topic later, but I didn't want this post to become unwieldy. I also intend to post about what went wrong (and still is going wrong) here in the USA, but that's definitely a much longer post.

I thought for years that I was probably developing multiple sclerosis because of increasingly troubling nerve problems.  A neurologist finally asked me to try eating gluten-free, and amazingly that change of diet made the major problems disappear.

Myelin is a fatty substance that surrounds neurons to improve their electrical signaling. When the myelin is damaged, then the neurons can still signal but just not as quickly or reliably.  Myelin is made not by the neurons themselves but by other brain cells called oligodendrocytes.

As I mentioned in my first link above, myelin issues are common on the autism spectrum. In the article below, researchers started from a very specific autism subset called Pitt-Hopkins syndrome.  They broadened their study, though, and examined 3 different autism mouse models. (Meaning, mice bred to exhibit autistic traits due to specific genes they carry.) Those 3 kinds of mice had mutations in PTEN, MECP2, and TCF4.


I've already checked these 3 genes on my 23AndMe.com results from ages ago, but I don't know how to evaluate my autism risk.  This study remains unpublished at the moment, so I can't find any specifics of SNP values that are associated with autism risk.  Their findings were merely presented at the 2019 Society for Neuroscience annual meeting.

That's not helpful.  I want objective details.