Personal genome analysis? And the meaning?

Is the gene profile priceless information or a senseless waste of money?
Vladimir Fradkin, Deutsche WelleThe human genome contains a lot of valuable information about his health – or rather, about his diseases.

And not only about classic hereditary diseases like, say, cystic fibrosis or muscular dystrophy, but also about genetic predisposition to such ailments as cancer, diabetes mellitus, schizophrenia, epilepsy, coronary heart disease and so on. At least that's what it looks like in theory. And the question of how much genetic tests allow in practice to assess the likelihood of developing certain diseases, how reliable such forecasts are and whether they can serve as a basis for preventive measures was hotly discussed by experts at the symposium on genetic diagnostics in Bonn.

Pure robberySince the technology of sequencing hereditary material is rapidly improving, a complete decoding of the individual genome of a patient in the very near future will cost no more than $ 1,000.

In other words, millions of people in developed countries will have access to comprehensive genetic information about themselves.

However, knowing does not mean understanding," says Norbert Paul from the Institute of History, Theory and Ethics of Medicine at the University of Mainz: "The genome today can no longer be considered as a static structure. Now we know that it is changing, dynamically transforming. And the more we know about it, the more vague this connection between cause and effect, between the features of the genome and diseases, seems. We have a better understanding of life in its complexity and versatility, but this does not mean that the availability of genetic information simplifies the approach to the problems of disease prevention."

Many of the genetic data available to doctors today about patients are completely useless or difficult to interpret. This applies, first of all, to the so-called "individual gene profiles", which many private firms specialize in compiling. They actively offer their services via the Internet. The prices are quite affordable – 300-400 euros – but is there much use from such gene profiles? The presence of a certain mutation in the gene involved in the development of, say, diabetes mellitus, does not mean that this disease will really manifest itself in this particular person. Here, very complex and largely unknown relationships with other genes, as well as with many external factors, are important. Such information confuses the user rather than helps to reduce the risk of disease," says Hans–Hilger Ropers from the Max Planck Society Research Institute for Molecular Genetics in Berlin.

"The development of all these complex polygenic hereditary diseases," he says, "depends, first of all, on factors unknown to us, second of all – on the environment, and only third of all – on genes. So, I consider it a crime to offer genetic tests for such diseases, as many companies do. This is pure robbery, fraud, and you need to be clearly aware of it."

Separating the wheat from the chaffThat is why most of the participants of the Bonn symposium called for scientists to focus their efforts on developing diagnostic tests that give reliable and unambiguous results.

This applies, for example, to cancer diagnosis," says John Burn from the Research Institute of Human Genetics at Newcastle University: "We will be able to separate the wheat from the chaff very quickly if we concentrate on useful genetic information and discard the one that defies interpretation – at least for now. This will greatly simplify both the diagnosis of cancer and its therapy."

Another example of such an applied approach to genome research can be the search for specific mutations that cause a particular hereditary ailment. So, Hans-Hilger Ropers presented in Bonn a technique that, he hopes, will allow determining whether the offspring of this particular couple will suffer from certain hereditary diseases. This is what worries potential parents," the scientist emphasizes: "The question is: am I going to get engaged or get married and have children, can you check me for hereditary diseases? Until now, we have had to answer: yes, we can, but you probably don't have a completely correct idea of what we are talking about. All we can do is eliminate certain risks. Everything else would cost an absolutely incredible amount, and besides, we just don't know a lot. Now, for the first time, we have the opportunity to check the genome for all hereditary diseases known to us at once with the help of a single diagnostic test."

It's a small matter: such a diagnostic test has yet to be developed. In the USA, research in this direction is in full swing. And the Berlin Institute of Molecular Genetics has already developed a technology that allows 2,500 genes involved in the development of hereditary ailments to be tested for dangerous mutations on one biochip at once.

Portal "Eternal youth" http://vechnayamolodost.ru05.03.2010