Gene, genetics, genome, and genomics all are derived from a Greek word – gen – meaning birth or origin.
Almost every aspect of health and disease is influenced in some way by the inherited information in cells, written in the chemical code of DNA and packaged in distinct units known as genes. The complete set of genes in the cells of a plant, animal, or person is called the genome. Genetics is the study of genes; genomics is the study of genomes.
Genes are pieces of DNA that carry – among other things – the blueprints for particular traits. Those genetic recipes tell the cell how to make the proteins that form the body’s structure and control vital functions. Virtually every cell in the body contains a complete copy of the human genome, which contains an estimated 20,000 to 25,000 genes located on 23 pairs of chromosomes, along with a vast amount of DNA that’s not organized into genes.
Although genetics and genomics are related, scientists define them differently. Genetics and genetic technologies focus on single or limited numbers of genes and their functions. Some DNA changes, or mutations, account for differences in traits among individuals, such as eye color. But in some cases, mutations in a single gene can cause cells to begin growing uncontrollably and form tumors. Certain gene mutations are associated with a higher risk of developing cancer. Many human traits, including common diseases, are determined by the interaction of many genes.
At centers like Dana-Farber, individuals and families can have genetic testing for the presence of mutated cancer-related genes to find out if they are at higher risk of developing certain malignancies.
The term genomics was coined in 1986 and refers to studying the entire genome of an individual organism or person. Many genomes of bacteria, plants, and animals have been sequenced, meaning their complete DNA scripts has been deciphered. The human DNA script was deciphered by the Human Genome Project, which was completed in 2003.
Since then, the field of genomics has made great progress in finding variations in multiple genes that affect health, disease, or drug response. Genomic research generates vast amounts of data and researchers have developed powerful computational bioinformatics tools to identify patterns that may lead to greater understanding or better treatments for disease.
This has been particularly important in advancing knowledge of how cancer develops and evolves. A government-led project, The Cancer Genome Atlas (TGCA) is compiling a catalog of genetic mutations and other changes underlying more than a dozen different types of cancer. Another effort, the International Cancer Genome Consortium, is working to obtain a comprehensive description of genomic and other changes in 50 different tumor types.