Human genome

Every cell of every living organism contains the master blueprint for all cellular structures and activities for the lifetime of the organism. The complete “set of instructions” for making a person is known as the human genome.

What is the Human Genome Project?
The U.S. Human Genome Project is an effort coordinated by the Department of Energy and the National Institutes of Health that aims to:

• identify all the approximately 30,000 genes in human DNA,
• determine the sequences of the 3 billion chemical base pairs that make up human DNA,
• store this information in databases,
• improve tools for data analysis,
• transfer related technologies to the private sector, and
• address the ethical, legal, and social issues (ELSI) that may arise from the project.

How can the genome affect medicine and science?
Technology and resources generated by the Human Genome Project and other genomics research are already having a major impact on research across the life sciences. The potential for commercial development of genomics research presents U.S. industry with a wealth of opportunities, and sales of DNA-based products and technologies in the biotechnology industry are projected to exceed $45 billion by 2009.

Some current and potential applications of genome research include:

• molecular medicine
• microbial genomics
• risk assessment
• bioarchaeology, anthropology, evolution, and human migration
• DNA forensics (identification)
• agriculture, livestock breeding, and bioprocessing

What are its implications for physicians?
As more genes and gene mutations are discovered through the Human Genome Project, the medical community will learn more about how genes work normally and how mutations adversely affect normal function.

Increasingly, medicine will become gene-based from its diagnostics to its therapeutics. Earlier recognition of disease susceptibility will offer new therapeutic interventions using traditional screening and surveillance methods as well as gene-based therapies. For example, recognizing that some hypertension is responsive to salt restriction could allow physicians to individualize therapy that will be more acceptable and more effective. Learning how antibiotic effectiveness may be genetically determined also can enhance success in the field of infectious diseases.

What are its implications for patients?
While modern medicine continues to make many advances, most physicians still must treat their patients’ conditions with a “one-size-fits-most” or trial and error approach. In other words, when a patient does not respond the way the majority of patients typically does to an infection or a prescribed medicine, then the physician is forced to change therapies until she finds one that works.

As the genome project unlocks how genetics influence reactions to diseases and treatments, the future eventually will bring more individualized therapy that better protects patients from adverse reactions. For example, how you differ from your neighbor at the genetic level may explain why you cannot tolerate codeine while your neighbor can, or why he developed signs of meningitis with exposure to a gastrointestinal virus while you developed only a mild stomachache.

While getting your personal genome sequenced will not be an option for quite some time, researchers are starting to build a catalog of human genomic variation that eventually will serve as the foundation for genetics-based treatments.

Sources
AMA Science
U.S. Department of Energy Office of Science, Office of Biological and Environmental Research, Human Genome Program