What is deafness genetic diagnosis? ”Why do parents with normal hearing give birth to deaf children?” , “Is it true that a combination of deaf and dumb people will only produce deaf offspring?” Why can’t a child hear after a single injection of gentamicin?”, “Why can’t a child hear anymore?” Why can’t we find the cause of our children’s hearing loss? The emergence of deafness genetic diagnosis can well explain the above questions. Deafness genetic diagnosis, also known as deafness molecular diagnosis or DNA diagnosis, is a technique of molecular biology and molecular genetics to detect whether the molecular structure level and expression level of deafness-related genes are abnormal, so as to make judgment on the cause of deafness. The most predominant deafness-causing genes in China’s deaf population include GJB2, SLC26A4 and mitochondrial 12SrRNA genes. More than half of Chinese patients with hereditary deafness are deafened by mutations in these genes. Who needs deafness genetic diagnosis and prenatal diagnosis? 1.Patients with deafness and their main family members: Genetic diagnosis of deafness can help to clarify the cause of deafness, and genetic testing of family members can help to clarify the carrier status of deafness gene mutation, so that scientific genetic counseling and guidance can be given before marriage and childbirth. Some normal hearing parents who have already given birth to a deaf child and wish to have a healthy hearing next generation can avoid having another deaf child in their family by providing preconception and prenatal genetic diagnosis to clarify the cause of the deaf child and prenatal guidance. 3. People to be treated with aminoglycosides (e.g. gentamicin, streptomycin, etc.): Testing for drug-sensitive mitochondrial mutations in people to be treated with aminoglycosides can help screen out sensitive individuals and give guidance on drug use to avoid the occurrence of deafness after drug use. 4. Newborns and infants: Hearing screening combined with deafness genetic testing in newborns and infants can detect late onset deafness early, which is important for early treatment and intervention of deafness. When should deafness genetic testing be performed? 1. Deafness genetic testing should be performed after deafness is detected 2. Deafness genetic testing should be performed before marriage for deaf youth 3. Before aminoglycoside medication 4. How to perform deafness genetic testing for newborns and infants? For deafness genetic diagnosis, only 3 ml of peripheral blood (a few drops of heel blood for infants) should be collected from the person to be tested, and the test should be performed by a professional. It is important to note that the results of the deafness genetic diagnosis should be interpreted and guided by a qualified physician after receiving them. Professional genetic testing for deafness is available at Kunming Medical College. The ENT Audiology Clinic is staffed by doctors who have been trained and qualified in genetic counseling for deafness by the Chinese Society of Genetics and the Association of Otolaryngologists for consultation and diagnosis.