An Overview of Epigenetics

Epigenetics is the study of the effect of your environment on gene expression. This includes the food you eat, the water you drink, the air you breath, the toxins you are exposed to, the exercise you do, the sleep you get, the relationships you have, your responses to stress, and what you think and believe.

Scientists are studying more about SNPs (single nucleotide polymorphism), methylation, and epigenetics. It’s all about your genes! We all have 46 chromosomes, 23 come from your mother, and 23 come from your father. Chromosomes have DNA information on them, which in turn make up a gene, which encodes for making proteins, which then determines a specific trait or function in our body. An SNP is a specific part of the gene that encodes for DNA expression of proteins or enzymes. Each SNP represents a difference in a single DNA building block, called a nucleotide. A “normal” SNP is called the wild type, as it is the most common.

If you happen to have one substitution of one nucleotide for another, then you are heterozygous for the SNP, meaning you have one normal copy, and one abnormal copy. Having one abnormal copy usually means you will have some alteration in activity or function. However, if you have 2 abnormal copies, then you are homozygous for that gene and can have a significant alteration in the function of the protein or enzyme that gene codes for. Your internal and external environment can alter the expression and function of your genes.

For instance, there are 2 main genes that can cause celiac disease, HLADQ2 and HLDQ8. About 40% of people in the US carry one of the celiac genes, meaning they carry the genetic predisposition to get celiac disease. However, only about 1% develop celiac disease. What makes some people get celiac disease and others not? The difference is their environment including gluten exposure.

Another example includes the SNP. if you are homozygous (2 copies of the gene) for the MTHFR C677T SNP, you have about a 70% reduction in your body’s ability to methylate folic acid in to 5-methyltetrahydrofolate, the active form your body can use. The term methylation simply means adding a methyl group (CH3). Now, if you are healthy, then you have already optimized function of the gene and have decreased the risk of having signs and symptoms or disease as a result of having the gene.