Is genetic testing reliable?
2020-04-22
By testing the genes, you can know what kind of cancer you may have in the future. This kind of new cancer prevention technology, which sounds very tall, is constantly emerging, and related products from hundreds to tens of thousands of yuan can be found online ...
01 How did the genetic test get angry?
Regarding genetic testing, one fact is that some people are often skeptical about genetic testing. In short, on the one hand, the genetic testing technology still has its shortcomings and limitations, on the other hand, it is because the public does not understand its inherent principles. Animals like humans are always afraid of things they don't understand.
In addition, the mixed fish market in the genetic testing market has made many people discouraged, that is, they are afraid to spend money unjustly and do not want to be a "white mouse" in vain.
Speaking of the rise of this concept, it can be said that it is the "Angelina effect."
▲ Angelina Jolie, famous all over the world for "Tomb Raider"
In 2012, Hollywood star Angelina Jolie learned that she was carrying a BRCA1 gene mutation that would increase the risk of breast and ovarian cancer, and she decided to perform a preventive bilateral mastectomy.
▲ The following year after the operation, Julie published her experience in the New York Times
The researchers found that within two weeks after Julie's article was published, the genetic testing rate for breast cancer increased by 64%. In contrast, the researchers pointed out that there was no such peak in the same period last year.
It can be said that Angelina contributed to the popularity of genetic testing.
What is the principle of genetic testing? Is it really useful? Next, I will explain to you.
02 Genetic testing is not mysterious
Many people's intuitive knowledge of genes is through science fiction blockbusters. For example, the mutants in "X-Men" were born due to genetic mutations; "Jurassic World" tells the story of scientists resurrecting dinosaurs by extracting DNA from fossils.
The scientific explanation is that DNA is the carrier of genetic information, mainly in the nucleus. The DNA molecule is a double helix structure, like a spiral ladder; the small unit on DNA that determines biological properties is the gene.
"Almost all diseases are related to genes." This is a new viewpoint proposed at the 2018 annual meeting of the Medical Genetics of the Guangdong Medical Association. Even "trauma" may be related to genes.
Genetic testing is actually not mysterious. It is a technique for detecting DNA through blood, other body fluids or cells. At present, it has been widely used in the detection of genetic diseases of newborns, the diagnosis of genetic diseases and the auxiliary diagnosis of some common diseases.
▲ According to reports, in 2017, the Dongguan Maternal and Child Health Hospital screened 43,000 fetuses through genetic testing technology and confirmed 112 cases of chromosomal diseases, effectively preventing birth defects such as mental retardation and multiple deformities.
In addition to genetic testing for newborns, in China, there are now 16 common cancer (including breast cancer, gastric cancer, prostate cancer, lung cancer, liver cancer) variant genes have been deciphered, can be used for predictive genetic testing.
▲ Incorrectly worn bras can also be a cause of breast cancer
At the same time, genetic testing has also been used for targeted therapy of tumors and drug treatment of clinical diseases.
For example, lung cancer, the world's largest cancer-cancer caused 8.8 million deaths in 2015, of which lung cancer alone accounted for 1.69 million cases, accounting for about 20% of all cancers.
80% of lung cancer patients are diagnosed at an advanced stage, and the 5-year survival rate of advanced lung cancer is extremely low. Once many patients are diagnosed, the most asked question is how long they can live.
However, 10 years after lung cancer-targeted drugs entered China, some patients with lung cancer have survived for more than 3 years.
The premise of targeted therapy is genetic testing.
So far, lung cancer patients with known genetic mutations have reached 62% of the total number of lung cancers. If these lung cancer patients can receive genetic testing in time, and find targeted drugs through genetic testing, it may prolong the survival time, improve the quality of life, and realize the life from cancer to cancer.
And many people care about the accuracy of genetic testing, there are relevant data for reference.
In 2015, Professor Ma Duan of Fudan University once said, "Currently, genetic testing warns of hereditary tumors, such as breast cancer, the accuracy rate has reached 50% to 80%. For some non-genetic tumors, such as lung cancer and gastric cancer, Predictive. "
For healthy people, especially the special population with a family history of cancer, the importance of genetic testing cannot be ignored.
03 Is it necessary for healthy people to do genetic testing?
As the incidence of cancer increases year by year, cancer genetic testing is becoming more popular. Many people realize the need to prevent cancer in advance, especially after family members and friends have cancer.
Everyone needs to understand their genes in order to explore the hidden problems behind the genes. Only by fully understanding the innate genes can the acquired nature avoid the risks in a targeted manner.
The following people, the importance of genetic testing is particularly prominent.
As in the Angelina Jolie incident, scientists discovered that there is an inevitable connection between BRCA mutations and breast and ovarian cancer. Scientific research also shows that IL13 gene mutation is more likely to cause hair loss and alopecia areata; ABCG2 gene mutation will affect the body's excretion of uric acid and increase the risk of gout; ANK2 gene mutation may cause cardiac dysfunction and even lead to sudden death ...
At present, there are more than 8,000 single-gene genetic diseases found in the world, and more than 100 are common, such as albinism and thalassemia1. Faced with so many genetic diseases, it is almost impossible to screen one by one because it is not only expensive but also time-consuming.
But one of the important meanings of genetic testing is to "focus on" your disease prevention.
The World Health Organization (WHO) shows that the occurrence of cancer is the result of the interaction between people's genetic factors and external factors.
If you can pass the genetic test and know the risk of a certain disease in advance, you will have time to avoid the bad environment and help prevent the disease.
For example, cancers such as breast cancer and colorectal cancer can be delayed or even avoided by changing life habits and paying attention to daily medical examinations as long as they can be predicted in advance.
