There are more than 20 million deaf people in China, of which hereditary deafness accounts for more than 50%. Hereditary deafness is mostly a recessive disease, which means that when both husband and wife are carriers, their own hearing is normal, but their children have a 25% chance of being deaf; and only when one of the husband and wife is a carrier, the children’s hearing is not affected. Currently, the percentage of normal people carrying the mutation gene for hereditary deafness is 5%-6%; therefore, it is not uncommon for couples with normal hearing to have deaf children, and the incidence of deafness among newborns has reached 1%-3%.γγThe occurrence of hereditary deafness is related to genetic mutations, and at least 200-300 genes related to deafness have been identified, with more than 1000 related mutation loci, which makes it very difficult to detect deafness susceptibility genes clinically. For Chinese, 80% of congenital deafness patients have the causative genes: GJB2 gene 235delC, SLC26A4 gene 919-2 A>G, and mitochondrial 12Sr RNA gene 1555A>G and 1494C>T. Performing tests for these four genes can clarify the cause of most inherited deafness. It is important for individuals, families and the next generation to be tested for deafness genes.1. Avoiding “one shot deafness”: People with normal hearing who develop hearing loss or deafness after using antibiotic drugs are commonly called “one shot deafness”. It was not known what caused it, but it is now clear that it is caused by damage to the mitochondrial genes carrying the aminoglycosides. Antibiotics are used to prevent infection and anti-inflammatory treatment. Aminoglycoside antibiotics, such as gentamicin, streptomycin, and butamycin, are widely used in clinical practice because they are cheap and effective. Some of these patients (mitochondrial DNA A1555G mutation) are extremely sensitive to these drugs, and deafness may occur even after a short application of these antibiotics in small doses. It is very important to test for deafness before administering the drug. In addition to clarifying the cause of deafness, it can also guide the use of medication for relatives of mothers who carry the mitochondrial DNA A1555G gene mutation but do not have the disease, so that they can avoid the tragedy of deafness from using aminoglycosides.γγ2. Slowing down the development of deafness: PDS gene mutation causes large vestibular canal syndrome. Such patients should try to avoid head trauma and other causes of increased cranial pressure, which can damage the inner ear, thus slowing down the development of deafness; GJB2 and GJB3 gene mutation can cause bilateral sensorineural deafness. If a pregnant woman has a positive test result, she should prompt her spouse to get tested for the deafness gene. If the spouse also has a positive result, there is a 1/4 chance that the fetus will develop deafness.