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Genetic Dragons The human genome project is nearing completion. Once we've mapped the human genome, we may have huge benefits for mankind. We could see the genes that cause deadly diseases being treated before birth. But we could also see mankind, for the first time, designing their offspring. Pat Pillai, "In Touch" presenter, goes behind the scenes to find out more.
Pat speaks to Dr Trevor Jenkins at Wits University about the human genome project. "Human genome project is a fascinating, modern enterprise setting out to determine the whole blueprint that determines the make-up of the human being," says Dr Jenkins.
Says Prof Michele Ramsay from Wits University: "The first trials for human gene therapy were done in 1990 and they have been very disappointing in several ways. One, they haven't actually managed to get the genes into the right places very effectively, and once they got them into there, they haven't managed to have them expressed and produce the proteins that are needed."
Like his father and grandfather before him, he carries genes that will give rise to prostate cancer as he grows older. Anxious for his child to avoid the same fate, the husband asks the doctors to prepare a special artificial chromosome containing made-to-order genes.
When he becomes an old man he will develop prostate cancer, but unlike his ancestors he will have the genetic repertoire to overcome the disease. One of the genes on the special chromosome will order the diseased prostate cells to self-destruct. He will beat prostate cancer because of steps that were taken before he was born.
"This is called germline engineering," explains Pat. "What it implies is that natural selection will cease to be an unconscious process. Human beings will seize control of their own evolution, choosing which traits to kill off and which to cultivate - pruning their own family trees." But if destroying cancer cells is one thing, creating traits is quite another. The same technology that allows doctors to eliminate or replace faulty genes, could in theory be used to give the couple what Newsweek has described as a designer baby - a baby with physical and perhaps even psychological qualities of the parents' choice. The psychology and behaviour of individuals is based not on genetics alone, but on the interaction of genes and the environment. "There are differences," says Prof Jenkins. "Because we are the products, not only because of our genes, but of our environments and perhaps even the position in which we were laying in the womb compared with our identical twin, say, will result in differences."
"But with the benefits, also come the problems: germline engineering decreases bio-diversity," says Pat. "By reducing the genetic options that exist now, certain genes that could have been vital to fight off a new virus, might be lost forever." What are some of the ethical questions surrounding the human applications of this new technology? First and foremost is consent - what if the child does not want a particular characteristic? Molecular biologists may have found a way around this problem by pairing the designer gene with an on-off switch. Having reached the age of consent, the child could choose whether to take a particular drug in order to activate the gene.
"Just because we have a better map, doesn't make us better sailors," says Pat . " As we wend our way through inner space there may yet be a few dragons to despatch, and the latest advances in genetics mean that some of them might be of our own making." CONTACTS:
Dr Trevor Jenkins
Prof Michele Ramsay
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"In the old days, cartographers cautioned seafarers against unchartered regions with the warning Here be Dragons," says Pat. With the benefit of twentieth century hindsight, their caution now looks a little like superstition. But there is a frontier that has yet to give up it's ghosts. It's not outer space, it's inner space! By constructing a map of the human genome - identifying each gene and relating it to its function - geneticists hope they are putting the last few dragons to rest."
The human genome project has enormous implications for medicine. At present, there are almost five thousand diseases that can be traced back to a genetic abnormality. Until now, these have been treated somatically, which means that healthy genes have been inserted into the cells of the diseased organ of the patient. The results have been less than convincing.
The ability to identify each gene will mean that inherited diseases can be cured before the sufferer is even born. A typical treatment might look like this - A husband and wife walk into an in-vitro fertilization clinic. They undergo genetic screening and discover that the husband possesses a deadly inherited disease.
Doctors fertilize a few of the woman's eggs with her husband's sperm and inject them with the custom-made chromosomes. The embryo is placed into the woman's uterus and nine months later a baby boy is born.
Using a technique called gene splicing whereby foreign genetic material is inserted into the DNA of an animal fetus, cattle have been made to grow bigger and faster and sheep have been engineered to produce human proteins in their milk. Some companies are breeding pigs with a human gene in an attempt to create animal organs that will not be rejected during human transplant operations.
Another fear is that only the wealthiest members of society could afford gene therapy, effectively creating a genetic underclass. Commercial exploitation of bioscience technologies is not new. Commerce has already influenced gene-splicing in farming and agriculture, so will gene therapies be available for all, or only those who can afford them? And will a new race of designed humans become the overclass of the next millennium?