Decoding the Environmental Genome
Por Cristina Hernández-Espinoza
The deciphering of 200 of the 554 genes considered "environmentally sensitive" has opened the door to greater understanding of our relationship with our surroundings and the human organism's reactions to specific problems, such as pollution.
SAN FRANCISCO, (Tierramérica).- What is the relationship between the development of an illness, the environment and our genes? Are there people who are genetically more vulnerable to pollution? Will we be able to control illnesses, like respiratory diseases, caused by environmental agents?
We could have conclusive responses to these questions in the near future, according to scientists working on the Environmental Genome Project (EGP). In April they completed efforts to decipher 200 of the 554 genes considered "environmentally sensitive" that they are working with.
This is an important step towards expanding knowledge about the gene-environment-disease relationship, Kenneth Olden, director of the National Institute of Environmental Health Sciences (NIEHS), told Tierramérica. This division of the U.S. Health Department set up the EGP in 1997.
The logic behind the EGP is that there exist specific genes (the parts of the cell nucleus that determine cell function and the transmission of hereditary traits) that play a role in virtually all human diseases, except some caused by trauma.
These genes confer an increase in the organism's sensitivity or resistance to environmental agents, which can be toxins, food or medicine.
The EGP's main objectives are to identify, characterize and record the variations of these genes.
The goal, says Olden, is to prevent adverse health effects arising from environmental exposure and to protect the most vulnerable individuals.
The EGP is fed by information generated by the broader Human Genome Project, which in April announced the decoding of the complete human gene sequence, which has some 2.91 billion base pairs and approximately 35,000 genes.
But the gene-environment relationship is proving to be extremely complex.
The experts have found that each individual responds differently to the same environmental exposure.
Gene characteristics govern the differences in the structures and activities of the enzymes responsible for processing toxins present in the air, water and food. If those enzymes do not function at appropriate levels for the organism, illness can develop in reaction to the exposure to the toxins.
To decipher the first group of genes, the EGP utilized 90 samples from people considered representative of the general United States population.
But not everyone supports the project. "Where were they 20 years ago when we reported high rates of cancer and health problems?" asks Judy Gobert, president of the non-governmental Indigenous Peoples Council on Biocolonialism, based in the western U.S. state of Nevada.
Gobert said in a conversation with Tierramérica that indigenous groups have genealogical and medical records that are of great interest for scientific research. "That is why they are coming to us now, but we are research subjects, not participants."
To handle questions and criticisms like Gobert's, the EGP has set up a program to handle the ethical, legal and social aspects of its endeavor.
Experimentation on humans, job discrimination, denial of medical insurance coverage and equity in access to genetic treatments are just some of the controversies that have been stirred up.
But "science never sleeps." The remaining 354 genes are expected to be decoded by 2005. Among the project's goals is to track genetic variations that "travel" from one generation to the next.
* Cristina Hernández-Espinoza is a Tierramérica contributing writer.