If it were not for the great variability among individuals, medicine might as well be a science, not an art.
If the nineteenth century was the Industrial Age and the twentieth the Atomic Age, it seems likely that the twenty-first century will be remembered as the Genomics Age. While this may seem presumptuous given that we have yet to experience a fifth of the century, the dramatic breakthroughs in genomics, culminating in the announcement by President Obama at the 2015 State of the Union address that called for investment in a large-scale precision medicine initiative, – an initiative that garnered bipartisan support and initial funding to the tune of $200 million – would seem to make this assertion plausible if the investment pays off. The use of the term “precision medicine” perhaps suggests that Precision Medicine might be the moniker attached to the age. This will depend on how successfully genoics and other ’omics will be integrated into medicine to improve outcomes and control cost, a question that will be explored in depth later in the chapter. Given the proliferation of prophetic and provocative terms in a world where knowledge and the ways in which it might be applied are changing rapidly, we need terms that have precise and fixed meanings, ones that are not stretched to fit every twist and turn in discovery and fashion.
The first to examine is the difference between genetic and genomic. The WHO defines genetics as “the study of heredity,” while genomics is defined as “as the study of genes and their functions, and related techniques.” The distinction that is most commonly made is that genetics concerns itself with the functioning and composition of the single gene whereas genomics addresses all genes and their interrelationships. This general distinction in biology is a bit clearer when applied to medicine. The specialty of clinical genetics has emerged, been identified, and been primarily limited to the diagnosis of so-called single gene disorders, also known as Mendelian disorders as for the most part they follow the rules of inheritance elucidated by Gregor Mendel in the nineteenth century.