The significance of genetic diagnosis and genetic counseling Since deafness genes are also carried at high rates in normal populations, e.g., GJB2 and SLC26A4 mutations are carried at 3% in normal hearing populations, mitochondrial DNA 1555 and 1494 mutations are carried at a rate of about 1/300, and normal hearing couples of childbearing age have a 6.3% chance of carrying at least one gene mutation. Therefore, we believe that screening for common deafness genes among normal hearing couples of childbearing age with no family history of deafness and providing genetic counseling for couples carrying deafness mutations based on this prospective prevention strategy will prevent a larger proportion of births with congenital recessive hereditary deafness than genetic counseling and prenatal diagnosis of deafness for normal couples who have already given birth to deaf children. It provides a theoretical basis and method for preventing the occurrence of hereditary deafness from the ground up. Therefore, genetic screening and prenatal diagnosis of deafness can generate great economic and social benefits, thus truly achieving the goal of improving the quality of the population and eugenic reproduction. I. Prevention to avoid the occurrence of deafness or to delay hearing loss through timely treatment Drug deafness is closely related to maternally inherited mitochondrial DNA 12SrRNA mutation-associated deafness. Carriers of the mutation are sensitive to aminoglycoside antibiotics, which is why the use of aminoglycoside antibiotics in individuals carrying this mutation can cause or worsen deafness. This is the reason why the use of aminoglycoside antibiotics in individuals carrying the mutation can cause or worsen deafness. This is what genetic testing for deafness is all about, not only to identify the cause of deafness, but also to provide individualized genetic counseling and preventive measures for deafness-prone individuals. Another type of deafness that can be effectively delayed by means of hearing loss is the large vestibular aqueduct syndrome caused by mutations in the SLC26A4 gene. This type of deafness is characterized by mostly normal hearing at birth, with fluctuating hearing loss during growth stimulated by predisposing factors, eventually progressing to severe or total deafness. This type of deafness is usually seen after the first or repeated occurrence of hearing loss. For this type of hearing loss, salvage treatment can be given as sudden deafness, and with timely treatment some patients will recover their hearing to varying degrees. After treatment, patients should also be instructed to prevent hearing loss, such as avoiding head trauma, strenuous sports, prohibiting inversions, preventing colds, and avoiding coughing and blowing the nose as hard as possible. In newborns, after genetic screening has detected and confirmed by CT of the temporal bone that the individual has large vestibular plumbing, preventive instructions can be given to their parents. II. Guidance and intervention of deafness-causing genetic diagnosis technology for marriage Deafness-causing genetic diagnosis is to detect the presence of deafness-causing genes through DNA testing of the patient, so as to clarify the cause of the disease and have good preventive significance for the reoccurrence of deafness. GJB2 is the most common gene responsible for hereditary non-syndromic deafness and is associated with about 21% of congenital deafness in China, followed by the PDS gene (i.e., large vestibular aqueduct) and the mitochondrial DNA A1555G mutation (1%-2%). Patients diagnosed with hereditary deafness can effectively reduce the risk rate of having a deaf child if they avoid choosing a deaf person with the same deafness-causing gene when choosing a spouse. For example, if the 21% of people who are currently deaf are GJB2-associated deaf, as mentioned above, and if these 21% of deaf people marry each other, i.e., both are deaf due to the GJB2 mutation, then 100% of their children will be deaf. The risk of having a deaf child is much lower if the GJB2 deaf person chooses a spouse from the remaining 80% (i.e., non-GJB2 deaf). Here, marriage of deaf people with the same deafness gene can be likened to consanguineous marriage and should therefore be avoided as much as possible. Current deafness genetic diagnostic techniques can diagnose the cause of about 60% of hereditary deafness, and the results can help them to choose the right spouse, thus effectively reducing the number of deaf children born. Genetic deafness refers to hearing loss caused by the transmission of genetic material from one parent to the offspring, and at least one parent is a carrier of the deafness gene. Parents who carry the recessive gene for deafness have a 25% risk of having another child who is deaf, while those with dominant deafness have a 50% risk of having another child. In China, about 30,000 deaf children are born each year, and about 300,000 couples of childbearing age who have had one deaf child are at risk of having another deaf child, and couples who have had a child with congenital deafness are themselves at high risk of having a deaf child. Deafness genetic diagnosis can play a role in the re-birth plan of about 60% of couples who have a child with congenital deafness, ensuring that the second child does not have the same defective gene that causes deafness, and providing a reliable technical guarantee and support for family planning and eugenics policies. Deafness genetic diagnosis technology also has the same effect on normal families. The high prevalence of deafness due to mutations in the GJB2 and PDS genes has been found to have a genetic basis, for example, the prevalence of GJB2 mutations in the normal population is about 3% in the West, while in the East Asian population it may be about 2%, and in our population it was found to be 3%. This means that normal people are also at risk of having children with GJB2 and PDS deafness. In this case, it is recommended that couples with childbearing potential should be screened for common deafness-causing mutations, and if both partners are found to have the same mutated deafness gene, guidance and intervention should be provided throughout the childbearing process, so as to prevent nearly 1/3 to 2/5 of congenital deafness births.