The first thing to know about genes is that genes are the basic unit of heredity, carrying DNA or RNA sequences with genetic information. Genetic testing is a technique to detect DNA through blood, other body fluids or cells, which is a method to take peripheral venous blood or other tissue cells of the examined person and amplify their genetic information, and then test the DNA molecular information in the cells of the examined person through specific equipment to analyze the types of genes and genetic defects contained therein and whether their expression functions are normal or not. It is a method to analyze the types of genes and gene defects contained in the cells of the examinee through specific equipment, and to analyze whether their expression functions are normal or not. Genetic testing is a method to extract some DNA information from the patient’s blood and some secretions of the patient, as well as his body fluids, which can be used to amplify the genes through the DNA information, and use the instrument to carry out the test.