Have you ever thought about what it would be like to be able to read your own personal book? Not necessarily a romance novel or a poetry collection, but a historical non-fiction book that has every letter and word describing your genetic makeup? This is the power of bioinformatics! Through the use of computers, statistics, and interdisciplinary scientists, bioinformatics can write the book of your genetic code, also known as your genome. Once complete, your genome book will contain 50,000 to 5 billion letters that make up all of your genetic characteristics. Then the question is, how do you read your genome book and make any sense of it? And what can it tell you anyway?
The first thing you need to figure out about your book is what language it is in. The cells of your body contain DNA, which makes up your genes and contains the “letters” for your genetic code. There are only four “letters” that make up DNA, but it is the pattern and order in which they are arranged that make the “words,” or genes. Surprisingly, everyone’s book is about 99% the same, yet it is the remaining 1% that makes people so different from each other.
Some of these changes are inherited from your parents, and some changes, or mutations, happen as your cells continuously divide. Identifying these differences and figuring out what they mean helps us determine why some people have blue eyes, why some people are susceptible to certain diseases, and even how some medical treatments will work.
An exciting medical application of these “genome books” is called personalized medicine, which uses all of this data to classify an individual’s disease, predict treatment outcomes, and target therapy directly at the cause of the disease. This is not to say that the medicine, until the last few years has not been personal. It simply suggests that with new technology – mainly the ability to decipher an individual’s entire genetic code (billions of data points) – we can compare individuals to identify the genomic cause of diseases and use that wealth of information to better target those causes directly.
In your book, the words, or genes, provide instructions for the cells in your body. The instructions consist of making proteins, turning genes on and off, and sending signals to cells, telling the cells what to do. When cells get the “wrong instructions”, they do not grow properly, leading to either cell death, or too much cell growth, like in cancer.
Let’s pretend that your genome is like a recipe for a cake. The recipe states the components you will need, in what amounts, and how they should be put together. You must make the cake, then make the icing. Along the way, mistakes can be made. Some changes would ruin the cake, and some would not. If the recipe calls for 2 eggs, but you use only 1 egg, the cake might be dry, but edible. If you forget the eggs all together, the batter probably will not work at all. If you forget the icing, the cake may still be good, but lacking something. If you forget the cake, the icing would have nowhere to go! In a very similar way your body is built and operated from a recipe, your DNA, and if mistakes, or mutations, get made, the consequences may be minor and unnoticeable, or they may be major and cause disease.
After the processes of bioinformatics are used to “write your book”, or sequence your genome, the next job is to “edit” the book. During the editing process, your sequence is checked for “spelling errors,” or changes in your sequence. It is this spell-checking process that distills the billions of letters down to a finite number of “errors,” or differences in your genome. In our next blog, we will look more closely at how these differences can then be interpreted to make your medicine more “personal.”
Julie Dragon, MD, and Marni Slavik, MD, are researchers in Microbiology and Molecular Genetics at the University of Vermont. Dr. Dragon is also the Director of the Molecular Bioinformatics Shared Resource (MBSR) for the University of Vermont College of Medicine.