Genes are a set of DNA molecules (nucleotides) that encode for functional molecules. They can be protein-coding or non-coding, with the differences between these two being about what type of functional molecule is produced by the gene. For example, a protein-coding gene can produce a molecule that changes a chemical into another form that we can use, whereas a non-coding gene could be used to produce a regulatory factor that increases the speed at which you make that first protein. Both types of genes are critical to life. Genes can also be referred to as the basic unit for heredity. This is because the DNA sequence that makes up your genes comes directly from your biological parents.
Genes are patterns of DNA that have an effect on living things, but why do we refer to them as DNA patterns and not just a fixed DNA sequence? The DNA sequence that makes up a gene can be different by one to several letters, which changes the outcome of what the gene makes. For example, between you the reader and me the writer we have the same genes for eye colour, however we may have a few DNA differences within that gene, which causes my eye colour to be brown and yours to be green.
When we have the same genes with variations in DNA sequences these are referred to as alleles. The gene definition is given by the function (eg. eye color), the differences are called variants (eg. brown eye color) and the set of different possibilities are known as alleles (eg. brown, blue, green, hazel, etc.).
These allele variants do not always cause changes that we can see, but can lead to problems within our bodies. These problems may affect your health, sensitivity to foods, or response to drugs.
Through sequencing and genetic analysis you can identify what allele or variant you have, which can inform the treatments you are prescribed to get you the best treatment possible the first time. To read more about genetics and sequencing explore our other learn pages.