Human genome may reveal key to healthy life. Scientists claim they will be able to unravel the secrets of how to live a healthy life from the human genome ahead of the 10th anniversary of the completion of the first draft of the 'book of life'.
It was hailed as a breakthrough that would bring about a “revolution” in medical science and was even described by some as a bigger achievement for mankind than landing on the Moon.
The announcement that scientists had for the first time been able to unravel and read entire human genome – the DNA instruction manual that underpins all human life – sparked hopes that some of the world’s most deadly diseases could finally be beaten.
But ten years after Tony Blair and Bill Clinton jointly announced that scientists had managed to decipher the book of life, many of the predicted benefits are still to be realised. Instead the human genome project has provided scientists with more questions than answers.
Yet as they prepare to mark the 10th anniversary of the completion of the first draft of the human genome, researchers now claim to be poised on the edge of a development that will finally bring benefits of the £2 billion project to everyone.
Hidden within our DNA, they say, are the secrets that will teach us how to live a healthy life.
Geneticists have discovered that the malfunctioning genes that cause many major diseases, including cancer, heart disease and diabetes, also carry distinctive signatures that can reveal what caused the malfunctions, or mutations, of the DNA in the first place.
“We can look at the genome of a cancer cell and we can see writ, as a kind of archaeological record, what caused those mutations maybe 20 or 30 years ago,” explained Professor Mike Stratton, director of the Wellcome Trust’s Sanger Institute – the British arm of the efforts to sequence the human genome, which is leading work to exploit the information it contains.
The Sanger Institute is now leading efforts to sequence the genomes of cancer cells taken from 25,000 patients around the world in a bid to unravel the full repertoire of genetic differences that make cancerous tissue different from healthy tissue.
Researchers on the project have already been able to compare the DNA taken from a lung cancer cell with that of a healthy cell and prove that it carries a characteristic set of differences that reveal the cancer was caused by smoking.
As they peer deeper into the genome for more of these telltale signatures, they hope they will be able to provide some definitive answers about the things that are good and bad for our health.
They may even be able to answer confusing debates about whether treats like chocolate, coffee and red wine are harmful or beneficial to our health, as current scientific studies have produced conflicting results.
Professor Stratton said: “Now we are going to look in 25,000 cancers over the next five to 10 years to look for other signatures and they will tell us what was involved in causing those cancers. This is going to be transforming.”
The completion of the first draft of the full sequence of the human genome on 26 June 2000 was the culmination of 10 years’ work and the contribution of hundreds of scientists from around the world. This week the Science Museum in London will open a new exhibition detailing some of the achievements since that date.
Before the publication of the genome, biologists believed our DNA would contain hundreds of thousands of genes needed to provide all the building blocks that make up the human body.
In a surprise that rocked the biological community to its core, however, the human genome project revealed there are just 22,000 genes encoded in human DNA.
It did not seem enough to explain our complex nature. Indeed a parasite made up of a single cell, called a trichomoniasis, has been found to have three times as many genes in its genome.
The findings have revealed that our genomes are far more complicated than was originally thought and it has become apparent that a single gene does not code for a single biological trait.
Height, for example, is an easily-observed trait that is passed down through families and was thought to have a simple genetic explanation.
In fact more than 100 genes have been identified to be implicated in determining height and scientists believe there could be up to 1,000.
“Effectively, the human genome was written in a different language from what we expected,” said Professor Steve Jones, a leading geneticist at University College London.
“Taking the genome apart was the easy bit, even though it was an extraordinary technical achievement. The hope was that by taking it apart, you would be able to infer how it worked but this has not happened.”
There were hopes the publication of the complete human genome would lead to the ability to identify new treatments for common diseases and patients could be screened for the risk of illness.
It was even claimed that by the time of Saturday’s anniversary, patients would be receiving personalised medicine where drugs would be tailored specifically to match an individuals own genetic make-up.
In reality, however, the progress has been far slower than expected and many of these predicted benefits have still to be realised.
The pharmaceutical industry has spend billions in the hope of reaping rewards from our genomes, but so far only a handful of drugs have made it to market.
“In many cases the hopes that simple answers would be found from the human genome have turned out to be a complete bust,” said Professor Jones. He believes that the genome has had other less obvious but significant benefits.
He said: “Genomes have transformed our idea of what life is and our ideas of human history. Everybody is essentially a living fossil as our entire evolutionary history is contained within our DNA.
Palaeontologists are now able to compare our modern human genome with genetic material obtained from fossilised bones of our forebears to draw new conclusions about what they may have been like and even how they spread around the globe.
Surprisingly we differ very little on a genetic level from other species. We share 96 per cent of our genes with chimpanzees while 80 per cent of our genes are the same as those found in mice.
There are now also hopes that new technology that is allowing the human genomes to be sequenced in a matter of weeks and months rather than years is also going to lead new ways of diagnosing diseases.
Francis Collins, the geneticist who led the Human Genome Project in the US, said: “There is variation between individuals that are now becoming clear. We have already discovered almost a 1,000 variations in the genome that play a role in human diseases.”
For Professor Jones, however, the human genome has also underlined how despite our technical achievements, humans are still subject to will of the environment around them.
“The more we are learning about our individual genetics, the more we should be concerned about the environment we place ourselves in,” he warned.
“It is strange, but rather than finding cures, perhaps genetics is going to focus our attention on behaving on a sensible manner.” ( telegraph.co.uk )
No comments:
Post a Comment