Your genome has been decoded. What's next?
Sally Lerman, "In the World of Science" # 8-2008
New genetic companies for about $ 1 thousand will scan the genome of anyone who wishes and inform the customer of the information they are interested in. This may be information concerning his pedigree, data on the state of health or genetic predisposition to a particular disease, and much more. The client can compare his genome with the genome of some celebrity or relatives and friends. Despite the impressive results and assurances of their infallibility, some experts believe that all the data posted on the companies' websites are more of an entertainment nature and have a very indirect relation to the stated goals.
Genetic testing "by order of the client" has been carried out for 10 years, and in recent years the range of genes covered by it has expanded immeasurably. Previously, most tests involved the identification of only a small number of gene variants, but today, with the improvement of the technique of using DNA chips, it has become possible to conduct fast and inexpensive testing of multiple genes at once. Recently, Navigenics in Redwood Shores and 23andMe in Mountain View (California), as well as deCODE in Reykjavik (Iceland), began conducting DNA scans to identify markers of more than 20 diseases. And the firm Knome in Cambridge (Massachusetts) has expressed its intention to join the project of Craig Venter and James Watson to create a data bank that includes sequenced and decoded personal genomes.
Currently, when geneticists have the latest techniques, control nucleotide sequences and extensive population data, it is possible to easily identify genes associated with a variety of pathologies or determining predisposition to them. Unfortunately, the information received is not exhaustive, and sometimes even turns out to be contradictory. This is warned by Muin Khoury, director of the Genomics Department of the Centers for Disease Control and Prevention. In his opinion, sequencing or scanning the genome for markers of predisposition to a particular disease "does not provide any valuable information."
Predisposition does not mean that the carrier of the corresponding gene will certainly get sick (with the exception of rare diseases associated with an anomaly in a single gene). The behavior of complex biological systems, such as the human body, is determined by interactions between many genes; RNA, chemical agents and other factors also play an important role. Complex diseases such as diabetes or cardiovascular pathologies develop under the influence of a wide variety of external factors in interaction with an indefinite number of genes.
With so many unknown parameters, it seems premature to make any predictions about health based on the results of genetic testing. This is Kouri's opinion. In addition, he emphasizes, it is not at all obvious that information about a genetic predisposition to diseases convinces people of the need to change something in their lives. And doctors themselves do not always know how to use the results of pharmacogenomic tests in practice. Moreover, as the research conducted in July 2006 showed. According to the Government Control Commission, in some cases, firms specializing in making dietary recommendations based on DNA testing of clients did not conduct any genetic analyses at all. The Commission concluded that these companies "misled consumers by making forecasts based on nothing."
New firms engaged in genotyping have decided to abandon the practice of forecasting altogether. They consider DNA scanning only as a new tool for obtaining medical information, which the client can dispose of at his discretion — consult with the attending physician or make an independent decision about diet or lifestyle. "Instead of waiting for science to reach a new level of development, it makes sense to correctly use what it has now," says Mary Baker, executive director of Navigenics. According to her, not all 1.8 million regions of the genome that her company scans today are informative, but as soon as they switch to a different quality, customers will immediately be able to take advantage of it. Navigenics plans to include in the database other information concerning, for example, the health status of family members, parents and more distant ancestors of the client, data on the reception of certain medications.
Some experts fear that such openness may lead to undesirable consequences. Since the practical benefits of a full—scale genome scan are not yet obvious, "an ordinary person may lose interest in it even before the situation changes, and this technique will manifest itself in all its might," says Sharon Terry, president of the Genetic Alliance advocacy group. In parallel with the development of tools such as guidelines for tracking the health status of all family members and their ancestors, or the creation of the Wiki Genetics website, experts from the Genetic Alliance firmly believe that it is necessary to take anti-discrimination measures, monitor compliance with the rights to privacy, improve the quality and accessibility of testing. So far, all attempts to make appropriate amendments to the legislation have not been successful.
Navigenics, 23andMe and deCODE claim that the owners of personal genetic data are the customers. But employees of companies do not block access to them for their partners — both commercial and those who are engaged in basic research and do not derive any profit from their activities.
Kouri believes that today the most accessible and effective tool of personalized medicine is a family medical history — it is a resource that costs almost nothing and at the same time allows you to detect the effects of many genes, take into account environmental and behavioral factors. But only a third of families have such information. Genotyping is undoubtedly a step forward in personalized medicine, "but it will take a long time until genetic data becomes a routine tool for doctors," Kouri is sure.
Portal "Eternal youth" www.vechnayamolodost.ru16.10.2008