Personal medicine: the way to the horizon
Genome on personality
Pyotr Smirnov, "Newspaper.Ru»For the last ten years we have been living in the era of personalized medicine: on February 15, 2001, the journal Nature published the first results of human genome sequencing.
Soon there were hints that we would not be afraid of the most incurable diseases, and even attempts to genetically calculate and construct a genome with the desired properties.
The coordinator of the Human Genome project Eric Lander and his colleagues in the anniversary issue of the same journal decided to sum up the scientific and practical results of the decade (Initial impact of the sequencing of the human genome).
Endless horizonFirst, we did find out that there are about three billion pairs of nucleotides and about 28 thousand genes in the human genome, 21 thousand of which encode proteins (that is, less than 1.5% of chromosomal DNA takes part in protein coding).
Secondly, such details of the work of our genome as transposons (mobile genetic elements) and a variety of non-coding sequences that "take care" of genes have become known.
Sequencing has phenomenal accuracy in reconstructing the evolutionary picture – now we can judge the degree of our kinship with Neanderthals or, if it seems interesting to someone, with yeast or mammoths. Now the best minds of molecular biology are struggling to decipher the "exogenome" – a set of modifications and add-ons that control the work of these 28 thousand genes.
Technological breakthroughAccording to the recognition of all those involved in the process, the sequencing method still remains the limiting factor.
For example, in a week in 1990, the sequencer was able to "read" 25,000 base pairs, in 2000 – 5 million, and now – 250 billion. This progress even surpasses Moore's rule for the semiconductor industry, which is that the number of transistors on a chip doubles every 24 months.
The demand for sequencing has led to the fact that all biotech giants (Life Science, Roche, Applied Biosystems, Illumina) have acquired a corresponding division. However, the prize for creating a technology that allows sequencing 98% of the human genome in 10 days for less than $10,000 still remains in the X PRIZE Foundation's bank account.
The sequencing results served as an impetus for the development of other areas. Bioinformatics was required to interpret molecular data: after all, every time scientists analyze the genome, they get not one sequence of three billion letters long, but a huge number of overlapping and repeating chains of several hundred letters, and even with typos. Other methods of molecular diagnostics (chips, PCR, etc.) were required to refine the data obtained and to apply them in practice: why read the entire sequence from each individual (sequence) when it is enough to check several sites for defects.
In practiceFor fans of eugenics, 2,850 genes have been identified for 165 different inherited diseases.
Now it is possible to diagnose the carrier in parents and calculate the probability of the disease in an unborn child. Patients in the dry balance are still content with only a "risk map" – data on mutations predisposing to the development of a particular disease. If desired, you will be tested (this does not require sequencing the entire genome – it is enough to analyze the area of interest) and determine which diseases you are predisposed to.
Among the well–studied conditions, there are already atherosclerosis, hypertension, macular degeneration, Crohn's disease, autoimmune conditions, psychiatric disorders, type II diabetes and, of course, the favorite of Western medicine - obesity, for which as many as 180 predisposing loci have been found. However, the doctor will only inform about the predisposition: the mentioned diseases can by no means be called hereditary, since lifestyle and bad habits have a much greater effect.
The ideal variant of personalized medicine, which the authors of the Human Genome project dreamed of 15 years ago, so far works well only in presentations, research projects and grant applications.
Currently, the recommendations for the treatment of rheumatoid arthritis or Crohn's disease do not shine with diversity, but more than fifty "risk" loci are known for each of them, and each of them is associated with a very specific link in the pathological cascade. Obviously, knowing a specific weak link, there will be no need to suppress the work of the entire system as a whole, as happens when taking the same glucocorticosteroids. The problem is that in practice, this individuality is limited only by diagnosis and prevention: doctors do not have tools for pinpoint influence on the disease.
The last word belongs to pharmaceutical corporations, which have always acted as an intermediary between science and the patient and – in monetary terms – determined the importance of discovery.
Portal "Eternal youth" http://vechnayamolodost.ru10.02.2011