Why all of the Variability? Genetic Expression and Individual Response

IMG_4197For the most part, you are everything you are because your DNA says so.  Your DNA is like a soft piece of clay that continually is moulded into something different based on what it is told to do.  We are all human but our DNA is not all the same.  Our eyes, hair and skin are different colour, we are different shapes, sizes and personalities; some have diabetes, heart disease, chronic pain, different basal metabolic rates, high blood pressure, and thyroid problems.  Some have arthritis, cancer, lupus, methylation issues, depression, anxiety, ADHD, food sensitivities, and gall bladder problems.  In short we have disease and discomfort.  Everyone has issues.


Are these problems due to chance?  To some it would appear so.  When you take a step back and look at the bigger picture of all influencers affecting your DNA, it becomes a much clearer picture.  With genetic research we have an entire universe open to our eyes that we knew was there all along, we just didn’t know what it did and still don’t know to what extent.  We are now getting a clearer picture of what genes are responsible for what processes.


Just what are genes, chromosomes and DNA?  Simply put DNA is what carries your genetic information in each of your body’s cells.  It is made up of continuing pairs of just four different bases.  A gene is a section of DNA.  Genes are the hotspots we zero in on that code for all of your body’s processes, from diseases like Huntington’s and cancer to cystic fibrosis and sickle cell anemia.  Genes “express” themselves in various ways, from hair and eye colour, to instructions on how to construct proteins from the 20 different amino acids in your body.  These proteins go on to include themselves in various tasks in the body, like a receptor in a membrane to taking part in a biochemical reaction for a cellular process like making energy.  There are an estimated 20,000-25,000 genes that code for protein synthesis alone.  Genes are packaged in bundles called chromosomes, of which humans have 23 pairs.


Now, about the word “expressed”.   Gene expression is the process whereby that gene’s information is used in the synthesis of a functional gene product.

Our genes get expressed in various ways.  Some are obvious like curly hair or how tall you are.  Genes can also express themselves in other ways based on what is presented to them from our diet or your environment.  We are now finding that some genes are able to recognize omega 3 fatty acids and correspondingly have a favorable effect on heart disease whereas some people are missing this gene response.  Fat, protein and carbohydrates all influence genes to respond in various ways.  Vitamins and minerals have the same effect on genes.  A deficiency in a mineral can cause a gene to respond and sometimes the level of that mineral in one person’s body needs to be higher than the next person because of a difference in their genetic makeup.  Heavy metal exposure and other environmental exposures can also have an effect on how your genes respond.


The problem is that our DNA isn’t 100% the same.  When our cells duplicate the chromosomes in preparation for cell division, there may be errors in exactly duplicating all of the DNA.  These SNIPS or single nucleotide polymorphisms are minor errors in the new DNA strand that may prevent the gene from working properly.  Some genes therefore do not respond the same in all people.  Some genes remain off until triggered to turn on for some reason.  These SNIPs can partly explain the difference in response between two people when taking the same drug,  or needing different doses of the same drug.  It can explain why one person takes a sleeping pill and feels nothing and someone else takes ¼ of the same tablet and sleeps all day.  This leads to obvious arguments as to how badly designed one of the studies was or an issue with the randomization procedure being incorrect.  Perhaps more correctly would be the observation that two different geographical areas were used in each study. Maybe these two areas have inherent differences in their DNA.  It also leads to almost anyone basically being able to hunt down some sort of study to back up what they are saying.  The assumption that a one size fits all medical model may cover everyone begins to fall apart when we look at the way our genes look at the world. It also explains how different systems in the body interact together rather than individual independent systems.






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