Genomics 101
According to the latest American Cancer Society statistics, about 40% of the population of the United States will develop cancer some time during their lifetime. In 2007, one in four deaths in the U.S.(559,650) is estimated to be due to cancer, the second most common cause of death in the U.S., exceeded only by heart disease. These numbers are rather daunting unless you consider that at least half are preventable by lifestyle adjustments. Cancer is caused by two factors – your genetics (nature) and your environment (nurture).
To understand your nature, you need to understand the relationship between DNA, genes, proteins and disease. The easiest way to begin your education is to view an excellent short video, courtesy of the National Human Genome Research Institute, called Exploring Our Molecular Selves. The more you understand, the better equipped you will be to ask questions of your health care providers. Educating yourself will ensure that you will be making an informed decision and working collaboratively with your medical specialist to select the best treatment available.
What are genes? The genetic instructions for the development and function of living organisms are contained in a large molecule called DNA. This molecule is divided up into 46 chromosomes, 23 inherited from your mother and 23 from your father. It makes it easier if you think of the chromosomes as books or better yet two 23 volume sets of encyclopedias. Each book can be broken down into genes or chapters. It’s those genes that direct the cell to assemble small molecules called amino acids into larger protein molecules.
This ladder-like DNA molecule that contains our personal instruction book is made up of four smaller molecules that create nature’s language: adenine (A), guanine (G), thymine (T), and cytosine (C). The rungs of the ladder, called bases, are our letters, and they pair to each other in a very specific way. The A always pairs to T and the G always pairs to C. No other arrangement is possible. These four letters can be arranged into sixty-four different three-letter “words”. These words are molecular codes that represent the twenty amino acids we just talked about, as well as some very important directions like start or stop making a protein.