It has been touted as nothing less than the "book of life" and the "language of God," proclaimed as both the greatest scientific breakthrough ever and, often in the same breath, the most ethically dangerous one.
Known as the Human Genome Project, news of its completion captivated the world nearly two months ago when an international group of scientists declared that they had deciphered 97 percent of the human genetic code – an announcement promising a veritable revolution in the medical and biological world.
Costa Rica is no exception. While the country was not a part of the actual project – a publicly funded consortium involving labs in the U.S., England, Japan, France, Germany and China – scientists here have a stake in the outcome and are following the latest genetic developments with particular interest.
Scientists here say that on-going studies of particular relevance to Costa Rica and other tropical countries have since taken on a renewed focus and energy.
"This is definitely not the end of something – it is just the beginning," summed up Dr. Fernando García, a microbiologist and director of the University of Costa Rica’s Center for Tropical Disease Research.
The $250-million Human Genome Project enabled scientists to decode the exact sequence of all 3 billion nucleotide bases that make up DNA (deoxyribonucleic acid), of which all living things are made. If printed out, the code – which is nothing more than the letters A, T, C and G repeated over and over in varying order – would fill 1,000 thousand-page telephone books. A public data base of the researchers’ findings, GenBank, is already available on the Internet at www.ncbi. nlm.nih.gov.
In fact, one young company, Rockville, MD.-based Celera Genomics, relied heavily on the public data to launch its own version of the project, which it unveiled in April.
With this painstaking, 10-year, multinational process of locating genes essentially complete, scientists will now take on the equally formidable challenge of understanding them.
Just like their counterparts worldwide, Costa Rican biologists have been working laboriously for 20 years to map and sequence human genes that cause certain illnesses or anomalies, ranging from manic-depressive syndrome and blindness to a form of deafness, known as "Monge deafness" that, so far, has only been seen in Costa Rica.
The recent discovery shaves years off the process, according to Pedro León Azofeifa, a head researcher at the University of Costa Rica’s Center for Molecular Biology.
"We’re really excited about this, because it reduces significantly the work we have to do in terms of mapping genes," he explained. "It can literally save us at least six years."
Using the genetic map, researchers can now pinpoint a gene in its particular region of a chromosome, facilitating research and analysis.
For the layperson, the implications of the breakthrough are thrilling but somewhat hard to digest, evoking futuristic notions of a world free of birth defects and diseases, like the one that served as the backdrop in Aldous Huxley’s classic science fiction novel, Brave New World.
Yet the ethical and social implications of using genetic information to eradicate defects have whipped up a storm of controversy that might be enough to stall that scenario – at least for now.
And the likelihood of ever living in a disease-free world is slim, according to García.
"It is practically impossible to eradicate the majority of infectious diseases. With this information, we can better control them and diminish the damage, but it is not realistic to think in terms of elimination," he explained.
García pointed out that many types of bacteria and viruses that cause infectious diseases have been around for nearly 4 billion years, whereas human beings have only about 100,000 years on the planet. And it is only in the last half century that real progress has been made in the study of such diseases.
"Sometimes it is easy to lose perspective," he added. "The capacity of diseases and viruses to survive is incredible, because they adapt much more easily and rapidly than human beings."
Garcia, who studies the genetic makeup of microorganisms as opposed to that of human beings, has spent years researching a bacterial agent called Helicobacter Pylori. This type of bacteria has been found to lead to stomach cancer, one of the leading killers in Costa Rica.
About 90 percent of the people living in Costa Rica are infected with some variation of the bacteria, as compared to 50 percent of the rest of the world’s population, he said. Of those infected, roughly 5 percent will contract stomach cancer, while another 10 to 20 percent will have some gastric problems, such as ulcers.
With the information yielded by the Human Genome Project, García said scientists eventually will be better able to determine if someone is genetically predisposed to develop stomach cancer. That way, doctors can focus on prevention or finding treatments much earlier.
Yet the horses are barely out of the starting gate. García anticipated that the process of identifying the bacterial genes that serve as "markers," or indicators, for the disease could take as long as five-to-10 or more years of research.
Next year, researchers will begin the task of analyzing the stomach tissue of nearly 600 subjects – each with a different type of the bacteria that cause stomach ailments – to look for these genetic markers.
Scientists here are also keen to apply new genome knowledge toward cures for potentially fatal diseases, such as malaria, dengue and tuberculosis – all of which are common in the tropics. "From the standpoint of infectious diseases, these are the three topics that are most important for public health," García said.
Isolating the bacterial or viral gene that is linked to these illnesses does not depend on the human genome, but, as with stomach cancer, the new windfall of knowledge dramatically broadens microbiologists’ analytical scope.
"We now have so much more information to draw on; the more information you have, the closer you are to answers," García said.
But don’t throw away your Malaria pills just yet. None of these tropical maladies will be gone by next week, and, in fact, vaccines might never be found.
As León, the molecular biologist, said: "(The Human Genome Project) has given us a sequence to work with, but it doesn’t tell us what the sequence is about. There is still a lot of work to be done."
