Genetic polymorphisms are mutations, called SNPs, that when expressed can cause a predisposition for a particular trait in the body. Many of these genes create a susceptibility for certain diseases or health conditions. Others affect the functions of enzymes and other chemical processes in the body. There are a number of different genetic polymorphisms that can affect the regulation of behavior in autism and ADHD.
We all have two sets of genes (from each parent) that are arranged in a double helix, pictured below. At the end of each strand is an allele that can be either positive or negative for each gene. It can be heterozygous (+/-) or homozygous (+/+ or -/-). A gene can be expressed if it is either +/+ or +/-, but is not always expressed.
A scientific field called epigenetics studies how our environment and nutrient status can turn genes on or off. This is called genetic “expression.” So, just because you have a particular gene, doesn’t mean it will be expressed. There are many factors that can influence this, such as exposure to toxins, nutrient status, stress, and lifestyle. And epigenetic changes are not a life sentence.1 Cleaning up your diet and environment can clean up your genes!
Let’s look at some specific genes that can affect behaviors in autism and ADHD. These have to do with different chemical processes in the body – detoxification, metabolism, methylation, and the functioning of neurotransmitters. When these processes aren’t working right, toxins build up, nutrients aren’t metabolized, and neurotransmitters don’t function well. This leads to irritability and reactions to certain foods, substances and chemicals.
COMT
The COMT gene has to do with the speed at which your liver breaks down catecholamines, excitatory neurotransmitters like dopamine and epinephrine (adrenaline), stimulants like caffeine, and even some antioxidant compounds like polyphenols. COMT can run either slow or fast. With a fast COMT, these are broken down quickly. With a slow COMT (+/+), they break down very slowly, causing them to build up. When your body can’t get rid of excess dopamine or stimulants, you’re more likely to be hyperactive, irritable, or have problems with self-regulation.
The metabolism of dopamine is the primary effect of a slow COMT on ADHD behaviors. Excess dopamine due to a COMT polymorphism can lead to a toxic form of dopamine called dopamine quinone, which is harmful to the brain.2 The most common medication used for ADHD, methylphenidate (Ritalin and Adderall) is a dopamine-boosting medication. However, the long-term effect of its use is that it creates excess dopamine and the harmful form, dopamine quinone. In effect, it can epigenetically turn a fast COMT into a slow COMT, exacerbating the problem.
COMT also affects processing of natural antioxidant pigments in fruits like berries. These are good for you, right? But if you have ASD or ADHD with a slow COMT, your body has trouble breaking these down and they accumulate in the body if eaten in excess. So eating a pint of blueberries can end up in dysregulation.
If you have a slow COMT, you should avoid stimulants like caffeine and limit or moderate your intake of the most colorful fruits and berries that have high amounts of antioxidant polyphenols.
CBS
The CBS gene regulates metabolism of sulfur. A person who is positive for the CBS mutation has trouble metabolizing sulfur. Sulfur is an important mineral that is good for us and required for many functions in the body. In fact, some of the most nutritious foods – cruciferous vegetables (broccoli, cauliflower, cabbage) – are high in sulfur. But too much sulfur builds up if you can’t process it. This affects digestion and behavioral regulation. Many people who are CBS +/+ have problems with gas and bloating. If you are CBS +/+ you should eat sulfur-containing foods like cruciferous vegetables, mushrooms, onions, garlic and eggs in moderation.
PON-1
PON-1 is a SNP that causes a difficulty processing and removing organophosphates, which are a kind of pesticide. It can also make it harder for the body to detoxify from air pollutants. Organophosphate interferes with acetylcholine (the chief neurotransmitter of the parasympathetic nervous system) in the brain.3 Avoid cigarette smoke, use a HEPA air purifier in your home, and eat clean, organic foods.
HLA-DRB1
HLA-DRB1 is a SNP that presents a genetic predisposition to have a negative reaction to vaccines. Most people do tolerate vaccines without having a reaction. But if you have this gene, you could have trouble clearing the vaccine ingredients from your body (particularly adjuvants) and react to them.4 Talk to your pediatrician about delaying or spreading out vaccinations to reduce the toxic load on the body.
Genetic testing
You can get genetic testing done by submitting a saliva sample to any of the popular genetic testing companies such as 23andme or ancestry.com. It’s not necessary to pay for the expensive health analysis, as they will not likely mention many of these particular SNPs. You can take your raw data and upload it to a site called MTHFRsupport.com, and for a small fee they will give you a report of most of the known possible SNPs so you can discover whether you are +/+, +/- or -/- for these particular genes.
Again, it’s important to note that just because you may have a particular gene, doesn’t mean it will be expressed! That depends on your environment and nutrient status and can change over time. See a functional medical doctor, naturopath, or nutritionist who can help you interpret your results and learn how to support your genes.
References
- Mukti, R.F., Islam, S. (2019). Epigenetic contributions on mental health, neurodevelopmental and neurodegenerative disorders. International journal of biosciences, 14 (1), 38-52. https://dx.doi.org/10.12692/ijb/14.1.38-52
- Lynch, B. (2018). Dirty genes. (pp.93-114) New York, NY: Harper Collins
- Ledowsky, C. (2020). Anxiety and Genetic Susceptibility to Environmental Toxins. https://healthmeans.com/talk/5758/348?currentTime=0
- O’Bryan, T. (2020). Best Tests and Treatment for Remediating Environmental Impacts and Optimizing Brain Health with Dr. Tom O’Bryan. https://www.drkarafitzgerald.com/2020/11/01/best-tests-and-treatment-for-remediating-environmental-impacts-and-optimizing-brain-health-with-dr-tom-obryan/