Introduction: In May 2013, Hollywood superstar Angelina Jolie suddenly announced that because genetic test results showed that she was at great risk of developing breast cancer, she made the decision to have both breasts removed in advance. After the decision was made, genetic testing suddenly became a buzzword pursued by the public and the media. At the same time, relevant businesses and hospitals took advantage of this opportunity and began to vigorously promote and publicize it. In February 2014, the Food and Drug Administration and the National Health and Family Planning Commission jointly issued a notice calling for the suspension of all genetic testing that had been carried out in the country, causing public opinion to be in an uproar. But this only means that for long-term development, the industry urgently needs to formulate relevant regulations, and at the same time, the public needs to be exposed to more information before deciding to undergo genetic testing.
To understand a novel, you not only need to know every word, but more importantly, you need to understand the order of the words. Sometimes, some governments will ban the publication of some books, not because the book uses illegal words, but simply because the author has arranged some words together in a special order, thus committing a taboo or violating certain controls. The author conveys information through word order, and the same is true for life, except that through just the four words TACG, it can pass on from generation to generation the information on how to construct the body of the new generation. This information is interpreted in the cells through wonderful tools to construct life. body and control its operation. If the initial information changes for various reasons, at some point, some pretty bad things will happen, such as hemophilia, which can be passed down from generation to generation, or various cancers.
The more we understand life, the more the scientific community realizes that if we want to understand the mysteries of the human body, we first need to read the word order of life and decipher its meaning. Fortunately, with the rapid improvement of automated sequencers and computer performance, by the year 2000, humans had basically read out the 3 billion words in their own genome. This has attracted many biotech companies and university research institutions to invest in finding valuable word sequences and deciphering the impact of these word sequences on the human body. So far, fruitful results have been achieved. This can be seen from some big headlines that pop up in the media from time to time. For example, the "single gene" that has suddenly become popular recently is one example of many research results. But if only these research results exist, the popularization of genetic testing will still not become a reality.
Today, the key reason why genetic testing has become a hot topic lies in the new generation of sequencers. The cost of sequencing has dropped dramatically and the speed of sequencing has greatly improved. Sequencing the first human genome cost approximately US$3 billion and took ten years to complete the draft. In the foreseeable future, the cost of sequencing will soon drop to $1,000, and the time will be shortened to 24 hours. This is the basis for promoting genetic testing to enter the homes of ordinary people. It has become possible both technically and cost-wise to sequence the genome of everyone.
There is no doubt that genes and diseases are closely related, and therefore humans have many strange genetic diseases. From the high frequency of sickle cell anemia in East Africa, where about one in four people has a "bad" gene, the information it provides changes just a little bit, and so does the protein it makes. A slight change has occurred, and the result is that the hemoglobin that transports oxygen in red blood cells has a higher probability of precipitating when oxygen is released, turning the red blood cells into a sickle, clogging capillaries, and causing various diseases. At the same time, the bone marrow There is no time to produce more red blood cells, and the oxygen-carrying capacity of the blood is therefore impaired. Most patients with these genetic diseases will die around the age of forty. At the same time, there are also extremely rare genetic diseases, such as unusually severe forms of obesity. In 1994, the leptin gene was discovered, and Amgen quickly obtained the patent for the gene at a cost of US$20 million. However, what dismays the company is that although there are so many obesity patients in the world, the company has only found a dozen patients who are caused by a genetic defect in this gene.
The more common single-gene genetic diseases in my country include favismosis, thalassemia, hemophilia, phenylketonuria (which seriously affects the development of the central nervous system), and color blindness.
After preliminary statistics, relevant experts believe that there are 79 common birth defects and genetic diseases in my country. Now that genetic testing technology has matured, it is necessary to use it to collect and investigate the distribution of these diseases across the country. Therefore, in August this year, relevant departments launched an investigation of major birth defects and genetic diseases and a collection of biological resources. This may mean that one day, the country may even provide certain types of genetic testing services for free in the same way as free vaccines. As for whether this is a good or bad thing, there will naturally be some quarrels at that time.
In addition to single-gene genetic diseases, there are many more familiar diseases that also have obvious genetic tendencies, such as hypertension, type 2 diabetes, etc. However, since both hypertension and type 2 diabetes are related to multiple genes, there are multiple possibilities for interpretation in the recognition and analysis of test results. This type of genetic-related disease involves many genes. Whether and when people with these "defective" genes develop the disease are often closely related to the environment and personal living habits. In fact, many people have not been tested at all. Just because they have these patients among their elders, they have begun to consciously change their living habits, such as switching to a low-sugar, low-salt, low-fat diet and increasing exercise. This reminds us that regardless of whether there is a test sheet, the pursuit of healthy life itself will not change. Could it be that, if due to various lucky factors, all suspected bad genes do not exist, can we indulge ourselves?
In this field, the academic debate is very fierce and even full of gunpowder. On one side are experts who study gene function, and on the other side are mainly from other professional fields, especially the education field. There is no doubt that some scientists will intentionally or unintentionally exaggerate the importance of their discoveries in order to publish papers and apply for funding. However, more misunderstandings mainly come from the media's inappropriate exaggeration of new research results out of context in order to attract readers. Publicity to attract attention.
Taking the "single" gene that has been heavily promoted by the media recently as an example, scientists from Peking University used hair to analyze the DNA of 579 college students and found that the 5-HTA1 gene has two slightly different word sequences. , they named them: G type and C type. Statistics show that 60% of people with G-type genes are single, while only half of people with C-type genes are single. This difference cannot be explained by differences in appearance or money. Therefore, there is a statistical correlation between this gene and whether you are single.
Opponents of this propaganda believe that this is typical genetic determinism and refute it, while supporters believe that knowing which genotype you have may help to deliberately improve your behavior. In most cases, such disputes are fought between chickens and ducks. After all, few molecular biologists really believe that genes determine everything. Human behavior is actually extremely complex, and the structure of the brain is not only related to the word order of genes, but also closely related to the uterine environment during embryonic development, and finally to the growth environment after birth. However, scientists cannot control these complex factors, and they can only try to use genes to provide a preliminary explanation for the complex nature of human nature. In fact, for complex behaviors in which multiple genes and environmental factors work together, the ability of a single gene to explain is very small, unless there are truly major abnormalities, such as some serious mental illnesses, severe depression, etc. . The actual performance of most people can be described by the classic normal distribution curve, that is, the status of most people is not very different. Only those distributed at both ends require special genetic reasons to explain.
If the information cannot be interpreted correctly, maybe it is better not to know? The pros and cons of genetic testing cannot be described in a short article. At the same time, new discoveries are emerging every day.
The author’s suggestion is that the current genetic testing technology is highly reliable for clear single-gene-related diseases. For polygene-related parts, it only has a certain value in probability. However, for any non-disease human behavior, it has a certain value. The results need to be viewed with an optimistic attitude, remembering that the brain has extraordinary plasticity, and the ancient saying that princes will live in harmony with one another still needs to be kept in mind. History throughout the ages has long denied the theory of blood, no matter how we The extent to which genes are understood, this fact that has long been verified, will only be finally confirmed, not the other way around.