When you research Autism Spectrum Disorders, you will quickly realise that there are as many theories on causes as there are researchers looking for answers. One fundamental aspect does seem to be undeniable however; there is a link to our genes.
Oddly, it doesn’t always express itself. An Aspie couple seem to stand a reasonable chance of having an NT baby, and similarly, ASD’s can seem to come out of thin air for NT couples, with seemingly no family history of such conditions. So what could possibly explain these discrepancies?
You may remember that back in 2003 that there was a huge buzz around The Human Genome Project. For the first time, scientists had mapped the human genome down to the last chromosome, and some serious work could begin, which would revolutionize out understanding of our selves. Politicians hailed this breakthrough as potentially one of the most important scientific advances since Antibiotics and Scientists received a great deal of funding to carry on this important work. Then everything went quiet.
Genes are quite complicated things. Your average bacterial cell has around 3200 genes. Yeast and other fungi have around 6000. The Fruit Fly, somewhere in the region of 13,000. A plant has around 25,000, while your average fruit has nearly 30,000. The Human Genome Project revealed something quite surprising. Human beings have around 21,000 genes. This simple fact surprised a lot of people, and forced geneticists around the world to rethink a lot of what they took for granted.
The genome is very much more than what we once thought, even just a few years ago. Indeed it turns out that it is a very adaptive system. Think of the genome as a scaffold that tells us roughly what our characteristics should be. That scaffold is a rough guide, and each part of this scaffold has something called an Epigene. An Epigene determines whether a gene expresses itself or not. But that isn’t all, you see Epigenes can change, they can adapt to their environment. They can turn genes on or off temporarily or permanently. When we exercise, for example, certain Epigenes change to allow us to process sugars more efficiently, making muscle fibres more efficient, albeit very temporarily. When we are exposed to toxins and diseases, and our cells are damaged, Epigenes play a roll there too, changing and helping to make repairs. Epigenes can behave like switched too, so for example, you can have two genetically identical twins, with exactly the same genome, but due to one having an Epigene switched on, there may be different characteristics or a different tendency toward a genetic condition.
Perhaps the most fascinating aspect of Epigenes is that they too can be hereditary. Studies performed in Sweden have found that in a remote and isolated village called Norrbotten, starvation due to instances of famine and crop failure went on to have detrimental health effects on at least two proceeding generations, despite having plenty of food, almost as if these children’s bodies were trying to adapt in the same way as their parents or grandparents bodies had to, despite now having ample food. This kind of quick single generational adaption makes perfect sense in terms of evolution. It allows your children to be prepared for the environment you live in.
The thing that is becoming clear about Epigenes is that lots of things can change them, not just the environment. Toxins, lifestyle and a million other unknowable factors could play a role in whether an Epigene is activated and passed on to a child.
The two things I am most commonly asked are: Where does Autism come from and Why is it on the rise?
I suspect autism related conditions have been around as long as we have. It doesn’t take much research to spot historical figures who certainly appeared to have some of the more common traits. That being the case, there have probably always been many people who have carried some genetic predisposition toward Autistic Spectrum Disorders of one kind or another, but those genes until recently have only occasionally been expressed. Most researchers agree that combinations of genetic & environmental factors are playing a role in this recent rise in people with ASD’s, and it is almost certain that Epigenes are a part of that puzzle. It could be lifestyle, it could be pollution or toxins. It could even be evolution experimenting.
Currently The Human Genome Project is collecting most data, in order to compare the full genetic makeup of as diverse a group of people as possible in order to identify the specific genetic functions. This is research that will certainly be going on for the rest of our lives. Despite the silence in the media, this project is benefiting people already, specifically in the study of cancer. Perhaps in time, the exact nature of developmental disorders such as those on the spectrum will become clear.