Lecture notes on the wonders of genetics
"An ordinary miracle of genetics": report from a lecture
Maxim Russo, <url>
June 13 in the framework of the project "Public lectures Polit.Denis Rebrikov, Doctor of Biological Sciences, Director of Science at the DNA Technology research and Production company, gave a lecture "An ordinary Miracle of Genetics".
The genome in encrypted form contains almost all information about the structure of an organism, for example, a person. The human genome consists of 23 pairs of chromosomes containing DNA molecules, and there are also individual DNA molecules in cellular organs – mitochondria. Genes are sections of a chromosome encoding individual traits. The DNA chain itself is formed by four types of nucleic bases: adenine (A), guanine (G), cytosine (C) and thymine (T). We can say that information about each of us is written using four letters. Three gigabytes of text that will fit on a regular USB flash drive.
What can these three gigabytes say about us? A lot. From skin color to infection resistance and temperament. When scientists fully decipher which gene of human DNA encodes what, and the individual genome itself will be recorded in the medical record, a person will be able to know the strengths and weaknesses of his body. Even now, doctors are able to determine from the genome such things as a predisposition to obesity, diabetes, atherosclerosis, coronary heart disease, osteoporosis, bronchial asthma, etc.
We should not forget about hereditary diseases, of which more than three hundred are currently known. Geneticists can assess the risk of developing such diseases in a child by examining the genotypes of his parents. For example, Ashkenazi Jews are recommended to be tested for 19 genes before marriage, the frequency of genes causing diseases is too high in the population.
At the moment, gene testing of newborns for phenylketonuria and cystic fibrosis is already being carried out in Russia. This makes it possible to start medical measures early. For example, in the case of phenylketonuria, the exclusion of foods containing phenylalanine from the child's food.
Predictive medicine is already developing, which determines the methods used to treat a person based on the data of his genome. Also, genetic information will help you choose the optimal living conditions for this patient, for example, climate.
A special area is pharmacogenomics, which helps to choose the optimal drugs based on the genotype, and, on the contrary, to avoid prescribing those drugs to which the patient has a genetically determined intolerance. At the moment, there are already more than thirty drugs for which, at the request of the US Food and Drug Administration, genotyping is mandatory before prescribing to a patient.
The picture is optimistic, but with new opportunities, humanity faces new questions, which Denis Rebrikov did not keep silent about in the lecture. Does the employer have the right to refuse employment on the basis of a genetic test? Wouldn't it be a new kind of discrimination if an insurance company dramatically increases the cost of health insurance if the client's genotype has a predisposition to some type of disease?
The dystopia in the form of a society that has mastered genetic technologies is shown in the American feature film "Gattaca", fragments of which were demonstrated during the lecture. The main character was conceived in the "usual" way, without prior genetic research, and immediately after birth, an analysis of his genome revealed a high risk of heart disease and a likely life expectancy of about 30 years. In the society shown in the film, the genotype of a child is preferred to plan in advance, making up with the help of genetic engineering the optimal combination of the genes of his parents. Those whose genes have undesirable properties cannot make a career, since genome analysis has become a common procedure when applying for a job, and become outcasts.
However, is genetics only of diagnostic value for practical medicine? Methods of gene therapy are already being developed, which makes it possible to introduce genetic constructs into the patient's cells that contain a properly functioning gene, for example, providing the synthesis of the necessary enzyme. To do this, a specially modified virus is created, which, being embedded in the DNA chain, inserts the necessary gene there. Clinical trials of gene therapy for a disease such as severe combined immunodeficiency are already underway. Patients with a mutation of one gene have impaired immunity, so they are very vulnerable to any infections. They are sometimes called "bubble babies" because they have to be in a sterile environment all the time.
If we go beyond medicine, we will find many areas of application of genetic knowledge there. Sports figures are closely following the achievements of genetics. Now geneticists are already able to determine, for example, the "sports profile" of a person, that is, whether he will be a sprinter or a stayer. Further prospects for the use of genetics are even wider. Screening a large population alone will help identify potential champions with a successful combination of genes – if you check the right genes in millions of people, there will be the right ones among them.
Finally, sooner or later they will move from simply identifying sports talents by genome to creating outstanding athletes with the help of genetic engineering. There is a name for this – "genetic doping". The methods are the same as with gene therapy, the desired gene will be inserted into the athlete's genome. The concept of genetic doping was first introduced by Andy Mia, a professor at the University of the West of Scotland, in the book "Genetically Modified Athletes" (2004).
Genetic technologies are becoming more and more accessible. According to the National Human Genome Research Institute, the cost of complete sequencing of the genome of one person in 2001 was 100 million US dollars, in 2007 – already 10 million, in 2009 – 100 thousand, in 2011 – 10 thousand, and now we are approaching one thousand dollars per genome. The sequencing process takes only two days nowadays. According to Denis Rebrikov's forecast, within five years the cost will decrease to hundreds of dollars. This will make full genome sequencing widely available to those who wish.
Portal "Eternal youth" http://vechnayamolodost.ru17.06.2013