Advances in the science of human genetics since 1980 (particularly the Human Genome Project) have prompted the development of techniques that identify a growing range of deleterious traits or predispositions. As researchers gain greater knowledge about the genetic components of many diseases or disorders, individuals are enabled to take precautionary measures reducing the chances of contracting an illness or mitigating its effects. In addition, genetic testing may be used to prevent the birth of offspring with a severely debilitating illness or disability.

Individuals, for example, may be tested for genetic traits indicating a proclivity for various forms of cancer or heart disease. If these genetic indications are present, individuals can avoid certain lifestyles or diets, take prescribed medications, or undergo invasive surgical techniques (in rare instances), which may help prevent the onset of cancer or heart disease....