You've probably heard that all humans are 99.9% the same. That's really amazing to think if you look around you and notice all the differences that we have, right? Well, that 0.1% represents about 3 million differences across the genome and 20 000 differences in our protein-encoding genes.
The home-based DNA tests that we sell are focused predominately on these protein-encoding genes as a basis to determine your genetic predisposition for many preventable, lifestyle-related, chronic diseases.
Right now you may consider yourself pretty healthy - eating a healthy diet, exercising, adding-in supplements and making time to relax. But what you may not know is whether your health choices are right for your genotype and phenotype.
When sitting with clients discussing their DNA results, I spend quite a bit of time giving them a crash course in genomics. I find that without doing this, many of us revert back to the belief that "your genes are your genes, and there is nothing you can do to change that" and as a result, this fatalistic belief may results in us not making the necessary health changes that we can and need to make.
So, let's take a deeper dive into the central dogma of genomics. This is the science behind DNA testing and is really important as it explains the flow of information from inside your cells to RNA to protein showing how your DNA information can actually inform your physical characteristics.
Step 1: Your DNA provides the template or information inside the nuclei of your cells.
Step 2: Transcription is the process by which your DNA information is transcribed into RNA information where only the important, exon sequence is kept for protein-encoding. Transcription can also play a more upstream role in regulating whether a gene is switched on or off.
Step 3: RNA transcription allows for the portability of your DNA information.
Step 4: Translation refers to the reading of the RNA information into a protein. Once all the amino acids are translated into a chain, they fold into the completed protein. I call this the "reading of the gene into its protein".
Step 5: Protein which can either have a structural or functional role in your cells, ultimately determine your traits
This diagram illustrates the central dogma process:
Genetic variations in genes refer to that 0.1 % that differentiates you from your mother, brother, best friend and the guy walking past you on the street! Your genetic variations are what is reported on after you have done a DNA test. Genetic variations in RNA (remember this is the readable and portable version of your genetic information) can either result in changes to the protein levels or protein function. That's why some practitioners will explain it to you as "you are a slow methylator" or "you are methylating at about 30%". What they are really talking about is these changes in protein levels caused by a genetic variation.
There are 4 main types of genetic variants:
- Silent variant where the change in the codon (the basic unit in the mature RNA sequence that encodes for an amino acid) does not result in a change in protein function
- Missense variant is a genetic variation that converts one amino acid in the chain to another
- Nonsense variant is when a STOP codon is translated that results in the termination of the protein. This has a very high impact on protein function.
- Frameshift variant occurs when all the amino acids after the genetic variation change. This is also considered a high impact variation.
Gene Function is in:
The genetic variation here means:
|Production||The production of the protein levels can be affected|
Can result in poor transportation of nutrients in and out of the cell
Reception or conversion
|Either the receptors can't receive the molecule or there is a compromised ability to convert the nutrient into its bioavailable form|
|That the removal or detox function is slowed down|
What are my genotype and phenotype?
Well, simply put your genotype is your unique genetic information, including your genetic variations. You can determine your genotype by doing DNA testing. Your phenotype is what you currently exhibit, and what you and others can observe. With lifestyle-related, chronic disease prevention and management, your phenotype refers to the symptoms that you report on such as inflammation, high bad cholesterol, hormone imbalances, thyroid issues, tiredness, lack of energy, stiffness, etc.
To determine your genotype, you can order your DNA test kit online from us HERE.
Penetrance and expressibility
One of the things that I really love about my job, is when I get to work with whole families. It is fascinating to compare the family pedigree, interrogating each individual member's genotype and then comparing everyone's phenotype. It's also a great reminder, that our genes are not our destiny and that even though two people can share the same genetic variation, they may not present with the trait associated with that gene. Why?
This is because of penetrance and expressivity. Simply put, penetrance refers to the fraction of people with a particular genotype that actually exhibits the associated phenotype. We often talk about genes having a high, medium or low penetrance. Interestingly, home-based DNA tests focus on medium to low penetrance genes as high penetrance genes (meaning that you have a high chance of being affected and you would require genetic counseling).
Medium to low penetrance could be caused by either genetic interaction (the gene doesn't act independently but rather in a pathway or with other genes) or environmental interaction. In Functional Medicine, it is the latter that we focus on in order to help our client's become healthier. Environmental interaction refers to what you expose your genes to in terms of nutrients and toxins.
Expressibility refers to the variability of the phenotype. So, if a mom and daughter both have the same genotype, why does one have more severe symptoms related to that genotype than the other? We see this as the "turning on and off" of the gene and when working with the genes that we test; we use changes in macro and micronutrients, exercise, hormone balancing, stress transformation in order to help you achieve that optimal expression of your genotype.
So, yes - your genes are not your destiny!
Changing your phenotype
In many ways, DNA testing is merely a tool in helping you to be healthier. It helps you to focus where your body needs the most support so that you can modify your phenotype. So, if you are like me and carry the genotype for obesity; it doesn't mean that you will be a 150kg obese, type 2 diabetic. It simply means that you have the potential but by changing your environment, you can switch this potential "on" or "off" with your choices. This is truly amazing.
That's where I come in! I help you to work to refine your health choices from your genotype, up.
You can book a session with me either in person, via ZOOM, Skype or WhatsApp.
The democratizing of medicine information makes it easy for all of us to understand important medical, genetic and biochemical processes. Once you know how your genetic information encodes important functional proteins in your body, understanding your own genes becomes really personal. And helpful!
CEO of MY DNA CHOICES
BA (Speech, Hearing & Lang Therapy) Hons | FMCHC | ReCODE Coach | Men's Health | HMX Genomics & Biochemistry (Candidate)