1) Aiding clinical diagnosis: Many diseases exhibit similar symptoms, making it difficult to make a differential diagnosis and easy to confuse. If genetic testing is used to find the cause of the disease at the genetic level, it can assist clinicians in differential diagnosis or even correct the clinical diagnosis.
For example, UW Genetics once conducted genetic testing for a family with a clinically suspected "congenital cataract-small cornea syndrome," and finally found that their family actually suffered from "vitreoretinal choroidopathy" instead of "congenital cataract-small cornea syndrome," and that their family had "vitreoretinal choroidopathy. "The genetic test revealed that the family actually had vitreoretinal chorioretinopathy rather than congenital cataract-small cornea syndrome, correcting the clinical diagnosis.
Another example is a specific type of diabetes called monogenic diabetes (caused by a mutation in a single gene, a Mendelian disease). Because of its genetic defects, the patient in the metabolic characteristics, clinical manifestations and treatment programs, etc., with type 1 or type 2 diabetes patients have obvious differences. However, due to a lack of awareness, monogenic diabetes is often mistaken for type 1 or type 2 diabetes. An epidemiologic survey in the United Kingdom showed that 80% of patients with late adolescent diabetes mellitus (MODY) were not correctly diagnosed. In studies of monogenic diabetes in Europe and the United States, it has been found that 10% of type 1 diabetes and 2-5% of type 2 diabetes are actually monogenic diabetes. Therefore, by screening the normal population, especially those with a family history of diabetes, for the causative genes of monogenic diabetes, genetic defects can be detected as early as possible, thus distinguishing patients with monogenic diabetes from those with type 1 or type 2 diabetes.
2) Guidance for treatment: The efficacy of treatment is related to many factors, and to troubleshoot external causes, differences in treatment between people are mainly influenced by genetic factors. Genetic testing can help individualize treatment, improve efficacy, and reduce the incidence of adverse effects.
3) Carrier screening: the most common is screening for Down syndrome. Traditional screening for Down syndrome is performed using serologic screening, with a detection rate of 65%-75%, which is easy to miss. Non-invasive prenatal genetic testing, however, can accurately screen children for Down syndrome and also includes screening for trisomy 18 and trisomy 13. In addition, screening for disease-causing genes in high-risk groups with a family history of certain single-gene genetic diseases (especially recessive genetic diseases) can detect the carriage of disease-causing genes in the family in time, and then analyze the risk of disease in the offspring, provide effective genetic information for family members, and prevent the defective genes from being passed on to the next generation.
4) Fertility guidance: The results of genetic testing, combined with the different inheritance patterns of the disease, can be used for fertility guidance through genetic counseling. Prenatal diagnosis (after natural pregnancy) or in vitro fertilization (IVF) combined with pre-implantation screening or diagnosis can help to produce healthy babies.
5) Provide accurate matching information for hematopoietic stem cell transplantation: When patients with thalassemia, mucopolysaccharides storage disease, leukemia, etc. need to be treated with hematopoietic stem cell transplantation, they have to undergo HLA typing to assess the incidence of rejection after transplantation. UW Genetics adopts gene sequencing, the "gold standard" of international HLA typing methods, to provide 4-digit high scores, which can provide accurate typing information for transplantation and find the most suitable donor faster. It can detect HLA-A, -B, -C, -G, -DRB1, -DRB3, -DRB4, -DRB5, -DQA1, -DQB1, -DPA1, -DPB1 and other multi-loci, which can comprehensively meet the needs of clinics, repositories and scientific research. Developed independently by UW Genetics, UW Genetics applies next-generation sequencing (NGS) to HLA testing, realizing a high-throughput and low-cost testing model for HLA.
2. Detection content:
Gene mutations that can be detected by genetic testing include: changes in the composition or arrangement of the bases of gene-specific DNA sequences due to various factors inside and outside the body, resulting in changes in the structure of the DNA at the primary level. Genetic testing mainly detects a variety of changes in the gene sequence, including changes in a single base, i.e., Single Nucleotide Variation (SNV), insertion and deletion of large or small sequence fragments (mutations in which one or more nucleotides are inserted/deleted in the DNA sequence, i.e., Insertion& Deletion, InDel), copy number variation (CNV), and copy number variation (CNV) of the sequence fragment, as well as mutations in the DNA sequence. Variant (CNV), Structure Variant (SV), Dynamic Mutation, etc. Currently, the most important types of mutations detected are Single Nucleotide Variant (SNV), Insertion and Deletion Mutation (InDel) and Copy Number Variant (CNV).
I. How long does it usually take for a genetic test to produce results:
The cycle of genetic testing varies according to the content of the test. The shortest is a week out of the results, the longest will take 2-3 months. The cycle also varies from one testing organization to another. In the case of non-invasive prenatal genetic testing, for example, mothers can check their test results within 15 working days from the day after the blood is drawn (working days do not include Saturdays, Sundays, and national holidays; the checking may be advanced or delayed in various regions, so please refer to the time informed by the hospital at the time of the test). In case of national holidays, the progress of sample testing will not be affected, but the collection of paper report may be delayed. The delay in the testing of individual mothers is due to the low concentration of fetal DNA in the blood samples of the mother and the high interference from the maternal background. In order to provide more accurate test results to the mothers, the testing time needs to be increased for further data analysis. In this case, the testing organization will need longer time to complete the test, but the extended testing time will not affect the accuracy of the test results.
Two, the basic information
Gene is a functional segment on the DNA molecule, is the basic unit of genetic information, is to determine the most basic factors of all biological species; genes determine the human birth, old age, disease and death, is the cause of health, beauty, longevity, is the manipulator and regulator of life. Therefore, where there is life, where there are genes, the existence and demise of all forms of life are determined by the genes, including your looks, height, weight, skin color, personality, etc. are inseparable from the genes.
Genetic testing is a technology that tests DNA through blood, other body fluids, or cells.
Three, understand the gene
Gene (Gene, Mendelian factor) is a DNA or RNA sequence that carries genetic information (i.e., a gene is a fragment of DNA or RNA that has a hereditary effect), also known as a genetic factor, is the basic unit of inheritance that controls traits. Genes express the genetic information they carry by directing the synthesis of proteins, thereby controlling the expression of traits in individual organisms.