Ben Lynch’s “Dirty Genes”, Best Seller in the United States published in 2018, opened to the door of the world of genetic polymorphisms to the general public. Six years later, I am finding more applications to this fascinating topic in my practice, as ressources around it become more available.
What is a Genetic Polymorphism?
The term polymorphism means several forms. Genetic polymorphism or “SNIP” (SNP for Single Nucleotid Polymorphism) is a difference in DNA sequence between individuals, groups or populations. It is, in other words, the different form that the same gene can take, and there are several normal forms of certain genes. The genes that control blood groups are an example of polymorphism.
I love the example that one of my functional analysis teachers makes, as it illustrates polymorphism quite well: “These are most often minor genetic variations affecting a single nucleotide in a gene (i.e. a letter changed on On average 30,000 letters for a gene). A large part of these variations are without consequences. It’s like a typo in the recipe for a kitchen book, it will not prevent you from making the recipe properly, in most cases. But, to continue the analogy, if instead of 6 eggs the recipe asks for 3 eggs (which is a small typo, a variation of a single character), it may be that the final product will be slightly modified. This is what Sometimes happens with SNPs “.
These variations are very common and more than 100 million SNP types have been identified. Most of these polymorphisms have no impact on our health or development, but some are of great importance. In particular, they can influence our reaction to certain drugs, our susceptibility to environmental factors, some toxins of which as well as susceptibility to developing specific diseases.
Available tests
After reading Ben Lynch’s book, I was curious to explore genetic testing. I ordered the 23andme test for my children, not to confirm their ethnic origin, but to discover their main SNPs. It is important to know that even when a SNP is present, it does not necessarily affect our health. Polymorphisms are not diagnoses, they are rather simply an information piece highlighting our individual susceptibilities. This can help support certain weaknesses with nutrition, supplementation, lifestyle (in short, by epigenetics). It’s a great prevention tool.
To date, several tests are available on the market, mainly in the US. At Alostase we offer the possibility to take the Igensis test, which allows to establish a custom nutritional strategy, depending on genetic polymorphisms. It is a fairly complete test which relates to a hundred genes and analyzes, among other things, the ability to detoxify, to metabolize vitamin B12 or proteins, carbohydrates or lipids.
My personal approach
When it comes to tests, I like the possibility of cherry picking, concentrating on a specific area. I particularly like to see what’s going on in the digestive system, and for that I like to research for a gene called FUT2, which makes it possible to determine whether the person has the capacity to produce a sufficient amount of mucus, a guarantee of a healthy intestine.
The most famous and currently researched polymorphism is the one affecting methyletetrahydrofolate reductase enzyme (MTHFR). This enzyme controls folate and their transformation in their active form in our body. Having a SNP on this gene can have repercussions on a myriad of biochemical processes that can affect the nervous system, our behavior, our cardiovascular health, false layers, and many other areas. Identifying a SNP on MTHFR can motivate to supplement regularly with B vitamins and/or encourage the consumption of dark green vegetables rich in folate. This is real individualisation and prevention.
Another gene that is highly regarded by some is APO E (Apolipoprotein E), associated in some studies with an increased risk for Alzheimer’s disease. But it seems that there are around forty genes and regions of the genome associated with this disease including allele 4 of the Apolipoprotein E (APOE4). To assess a person’s risk to one day develop Alzheimer’s disease, all variables and other risk factors have to be taken into account. As we know today, most affections are multifactorial. They partly depend on genetics, but above all on epigenetics (our environment, food and lifestyle). And we are only at the very beginning of understanding how polymorphisms really work.
Another screening that I value concerns genetic polymorphism affecting the expression of a gene named Dio 2, coding for an enzyme called 5′-desiodasis. This enzyme is responsible for the transformation of T4, a form of storage of thyroid hormones, in T3.
Conclusion
The evolution of nutrition and medicine seems more and more linked to genomics. This should allow an ever more targeted, personalized approach to health, allowing individuals to take part in their health through prevention and healthier lifestyles.
Pages could be written on this exciting topic, but I hope that this brief version will be a good introduction if you are not familiar with it.
And if you are as curious as I am, you can make an appointment to discuss your options for testing your polymorphisms.
