Genetics is the study of how biological information is passed on and inherited, and how this process leads to the variation we see in the world around us.
The basic units of inheritable biological information are genes, which are segments of DNA (short for deoxyribonucleic acid) molecules that contains the instructions for how, when and where your body makes each of the many thousands of proteins required for life.
There are over 20,000 different genes in the human body, the sum total of which make up your genome.
Each gene is comprised of smaller molecules known as nucleotides, which come in 4 varieties represented by the letters A, T, C and G. The order that these letters are in determines the genes function.
On average, people are 99.5 % genetically identical, meaning the majority of the genetic information they carry is the same. However at some key points of variation, these nucleotides can come in many forms – known as a polymorphism. It's these differences that make us who we are.
When this occurs at a single genetic position, it is known as a single nucleotide polymorphism, or SNP.
SNPs influence the overall function of the gene by slightly changing the instructions, similar to how changing one word in a sentence can have a big effect on it's meaning.
Polymorphisms are variations that occur in over 1% of the population, so this suggest they serve a function. This differentiates them from mutations, which appear at frequencies too low to suggest a definite function.
Polymorphisms are neither good or bad, they are simply differences. Knowing and understanding these differences empowers us with valuable information for shaping our exercise and nutrition choices.