"When I got the genetic test report, the doctor said that I was positive for NPM 1 gene mutation, and I was a leukemia that was easy to alleviate, and my prognosis would be better." Ms. Wang, a native of Jiangyin, said that two weeks ago, she was diagnosed with acute myeloid leukemia in the First Hospital of the city, and the whole family fell into despair. Recently, she got the genetic test results, and finally she can feel at ease. "The doctor said that in my case, as long as it is well treated, the five-year survival rate is very high."
Cao, director of the hematology department of the First Hospital, said that since the "precision medical care" plan was put forward in the United States on 20 15, the cornerstone of "precision"-gene-related testing has become more and more "hot". "Genetic testing like leukemia can make doctors more clear about the cause and formulate corresponding treatment methods. The effect of treating leukemia is greatly improved than in the past."
In recent years, genetic testing has been widely used in clinical medicine, but market chaos has also followed. Some genetic testing institutions are overpriced, some test results are inaccurate, and some fool patients into doing unnecessary tests. ...
During the interview, many doctors reminded that consumers should choose regular medical institutions and inspection institutions with professional laboratories and service qualifications for genetic testing, and don't blindly trust other institutions and online stores that claim to be able to carry out genetic testing.
Third-party organizations generally only do testing and do not provide diagnosis.
Genetic testing refers to extracting and amplifying the genetic information of the blood and oral mucosa cells of the subjects, and then detecting the genetic information of DNA molecules in the cells of the subjects through gene chips and other technologies, and analyzing the information including disease risk, drug safety, nutritional metabolism and so on.
On an online shopping platform, the reporter found that there are many kinds of testing items such as "beauty gene testing", "obesity management gene testing", "children's multiple intelligence gene testing" and "tumor gene testing", and the price gap is also very large, ranging from several hundred yuan to ten thousand yuan.
Yu, deputy director of the laboratory of the Municipal Maternal and Child Health Hospital, said that genetic testing is actually a systematic and comprehensive system, including experiment, clinic and management. Many projects belong to the category of national special technical management, which need to pass strict qualification examination and approval, and there are a series of technical specifications and standards. Even formal third-party organizations only do testing and do not provide diagnostic services.
As for the price, the price of genetic testing products in formal institutions is charged according to the testing items. A single genetic test costs several hundred yuan, and packages containing more items will reach thousands or even tens of thousands. However, there are some genetic testing enterprises with no corresponding service qualification in the market, which make use of ordinary people's ignorance of genetic science and technology information to launch false high-priced testing packages to earn profits.
"In addition, in addition to giving professional testing information in the genetic testing report, genetic testing institutions should also give an easy-to-understand interpretation for consumers to understand." Yu said.
Is the genetic physical examination reliable?
A4 size, more than 100 pages thick. A few days ago, Ms. Qin (pseudonym) got her own genetic physical examination report, but she felt that she was facing a sealed book. "It's all technical terms and data. The only thing I can understand is that I carry genes that are prone to lung cancer. " To this end, Ms. Qin fidgeted for a whole week and finally went to the hospital for consultation at her daughter's suggestion.
Zhou Tong, director of the Oncology Department of the Fourth Municipal Hospital, explained to her: "Most tumors are affected by many factors, not just genes. Your susceptibility to lung cancer is indeed 50% higher than that of ordinary people. But do you know the probability of smoking getting lung cancer? It is ten times and twenty times the risk of ordinary people! "
Hearing this, Ms. Qin breathed a sigh of relief: "At that time, the insurance company said that there were advanced physical examination items, which could be used for health management and prediction by detecting genes. I didn't expect this physical examination to be just an examination. Regardless of the explanation, I finally scared myself. "
"With the advancement of technology, it has become possible to detect the whole genome in clinic, but the final data capacity can be as high as more than 10 g. First of all, the test results must be obtained through professional bioinformatics analysis, and the final interpretation is very complicated, which is difficult for non-specialist experts to be competent." Zhou told reporters that in the whole genome test results, only a small number of clinically significant gene "passwords" have been cracked, so this test should be decided by doctors according to actual needs. At present, this technology is mainly used in clinical diagnosis and individualized treatment.
Zhou reminded not to blindly carry out genetic testing for screening, consult a doctor first, and then carry out targeted screening after determining that it is a high-risk group, which is more cost-saving and safer.
The doctor-patient relationship behind the deification of genetic testing
Prenatal detection of fetal free DNA in maternal peripheral blood (people used to call it "non-invasive DNA screening") is a widely used genetic testing project in prenatal diagnosis. Because genetic testing itself is too deified, prenatal diagnosis itself has become a risky job for medical workers.
Genetic testing has been deified, which makes many people think that they have been diagnosed by such cutting-edge medical technology and there can be no more problems. "For the most common birth defects (three body 2 1, 18, 13), the accuracy of prenatal detection of fetal free DNA in maternal peripheral blood is over 95%." Yan Bin explained, "The accuracy is very high, but it is not 100%. It is also a test of these chromosomes, and there are hidden dangers on other chromosomes. This test cannot be reflected. "
Another situation that will put doctors and patients in a dilemma is that genetic testing may be more sensitive to the future. How do you choose this possible "future"? "Prenatal genetic diagnosis will find some non-fatal diseases that may exist in the fetus. These diseases will not affect the child's life, but will affect the child's future quality of life to varying degrees. In this case, how to choose? " Yu said, "We will carefully analyze the advantages and disadvantages of these non-fatal diseases for pregnant women and her family. As for the final choice, they will have their own answers."
These genetic tests are widely used in our city at present.
The reporter learned from the Municipal Maternal and Child Health Hospital that chromosome microarray gene testing has been carried out independently for one month, with an average of more than 30 citizens coming to test every week. Yu said: "Since 20 15, the hospital has independently carried out prenatal detection of fetal free DNA in maternal peripheral blood, personalized folic acid gene detection, chromosome microarray gene detection, Y chromosome microdeletion detection and other projects. More and more citizens are concerned about the relevant trends, and even many people take the initiative to come to the clinic for consultation. Among them, more than 7,900 cases of fetal free DNA in the peripheral blood of pregnant women have been independently tested. "
Mutation detection of CTDNA gene, commonly known as whole gene detection, has been independently carried out in the Fourth Hospital for nearly two years, and is currently the most widely used in patients with advanced lung cancer. "Basically, most patients with advanced lung cancer can choose CTDNA to determine the direction of targeted drugs, because the drugs for lung targeted therapy are very rich, and this test is of greater significance to lung tumors at present." Zhou explained.
Prenatal detection of fetal free DNA in peripheral blood of pregnant women
"Prenatal detection of fetal free DNA in maternal peripheral blood" is commonly known as non-invasive prenatal DNA screening.
Prenatal diagnosis and screening methods include invasive and non-invasive methods. Invasive prenatal diagnosis, including villus biopsy, amniocentesis and umbilical cord blood puncture, is the "gold standard" of prenatal diagnosis. However, due to the need for invasive procedures, it may cause serious complications such as abortion or intrauterine infection, which makes many pregnant women discouraged.
Non-invasive DNA prenatal screening is very convenient, just draw blood.
Applicable people
A few milliliters of pregnant women's peripheral blood were taken from 0/2 week of pregnancy to 22+6 weeks of pregnancy, and the free DNA fragments (including fetal free DNA) in pregnant women's peripheral blood were sequenced by the new generation DNA sequencing technology, so as to obtain fetal genetic information and judge the risk of fetal-related chromosome diseases, with high detection rate. For the most common birth defects (2 1 65438+), the report usually comes out in about 3 weeks. The disadvantage is that the test items are limited. If the test result is high risk, interventional prenatal diagnosis is still needed.
Mutation detection of CTDNA gene
Detection of circulating tumor DNA(ctDNA) gene mutation has certain clinical application value for targeted tumor therapy, early treatment of response evaluation and real-time evaluation of drug resistance monitoring. Due to the limitation of tissue samples, free DNA in patients' plasma is gradually used to detect tumor gene mutation in clinic.
Its advantage lies in knowing four or five hundred genes in the whole body through blood drawing, but its limitation lies in that up to now, there are only dozens of truly valuable gene information in clinic.
Applicable people
1. Patients with advanced cancer cannot obtain biopsy samples before receiving targeted therapy.
2. Tumor patients are used to dynamically monitor the therapeutic effect during the treatment.
Xu Qianwei, Li Wen and Hu Ping