One thing that can be done with genetic testing is prenatal screening on prospective parents. At this time there's not a lot of therapy for birth defects, so the main option is termination of the pregnancy. A large percentage of the population is opposed to abortion, and thus, opposed to genetic testing that may lead to abortion. Even those people who are not opposed to abortion in cases of birth defects or life threatening situations, may feel differently about testing to determine the sex of the fetus, before deciding on abortion. All diseases have a genetic component.
All human behavior has a genetic component.
One problem may be that people have the perception that if a particular gene is in the DNA, then the characteristic will inevitably be expressed. People don't understand about heterozygotes and gene-environment interactions. Genetic testing and identification does not mean genetic determinism . The environmental component of disease is a major factor, so we're modifying our behavior and economics based on the genetic information. For instance, a level of homocysteine higher than normal is an indicator of a higher risk of heart disease.