Quiz 22: Genomics


The public Human Genome Project took blood and sperm samples from a dozen anonymous donors and combined them. The project's commercial rival, Celera Genomics, put an ad in The Washington Post , selected 30 men and women from a variety of ethnic backgrounds and used six of them. The source of the DNA is not really critical since all humans share 99.9% genetic identity with one another.

Some of the advantages of the project are that it will improve our knowledge of gene expression, help to elucidate the function of the large proportion of DNA we know little about, lead to the discovery of new means to diagnose and treat certain genetic disease, allow researchers to go directly from a trait to a gene, and increase our taxonomic understanding. One often cited disadvantage is the fact that 97% of the genomic information generated by the project does not code for protein (and is sometimes referred to as "junk" DNA). Furthermore, genetic tests for many inherited disease susceptibilities will become available long before new treatments, and this may cause patients anguish knowing that they have an untreatable disease. There is concern that some of the genetic information obtained from new genetics tests may be misused by insurance companies and employers and that genome based tests and therapies may add to the increasing gap between rich and poor countries in the level of health care and quality of life. At present it is not clear how the patenting of human genes and DNA affect the cost of publicly funded research and health care.

Several obstacles stand in the way of the widespread use of a genetic test. The test must be simple, cost-effective, and accurate. The test must also be validated in larger populations in order to make sure that disease susceptibility is caused by the mutation being tested for and not by some other genetic or environmental factors. Widespread testing requires health care professionals educated in the interpretation of such tests and currently most primary care physicians do not receive this training. Serious ethical issues need to be resolved concerning confidentiality and discrimination. Regulations and legislation will be required in order to protect people from discrimination based on genetic testing information.