You may still remember the exquisite and shocking dance “Thousand Hands Guanyin” at the Spring Festival Gala in 2005. While we were impressed by the deaf performers’ exquisite dancing skills, we also sighed for the silent world they live in. In 2006, China’s second sample survey of people with disabilities showed that the total number of people with disabilities in the country was more than 80 million, with 27.8 million people with hearing and speech disabilities, including 20.04 million with hearing disabilities, accounting for 24.16 percent of the total number of people with disabilities, and 800,000 deaf children under the age of 7 with hearing and speech disabilities. The number of deaf children under the age of 7 is 800,000 and is increasing at the rate of 30,000 new children per year. Deafness in childhood is very common, with an average of one to three hearing impaired children per 1,000 births. Deafness causes tremendous pain for both parents and children and is a disaster for the average family. Some parents take their deaf children everywhere to seek medical help, only to be disappointed. Some children are born with normal hearing, but soon afterwards they experience hearing loss and fluctuations for no apparent reason; other children are even left in a world of silence for the rest of their lives. Happily, we are now able to diagnose deafness genetically and identify the “culprits” of deafness so that we can intervene early. This is because we have a better understanding of the mechanisms by which deafness occurs. These deafnesses that occur in childhood can be divided into two main categories according to the cause: non-genetic deafness and genetic deafness, with each category accounting for roughly half of the deafness. The causes of non-genetic deafness are mostly related to many factors such as viral infections (e.g., colds) in the mother during pregnancy or in the child after birth, medications, birth injuries, hypoxic asphyxia, and premature birth weight; genetic deafness is caused by the presence of pathological mutations in the genetic material – genes – associated with deafness; GJB2, PDS and mitochondrial GJB2, PDS and mitochondrial genes are the most frequently mutated genes. These gene mutations can occur in recessive hereditary deafness. The small size of families in China at present often does not have deafness occurring in the family, masking the cause of deafness. In fact, both parents must be carriers of a certain gene mutation for one quarter of their children to get the disease, while the parents have normal hearing. Therefore, in single-child families, the disease is mostly manifested as an epidemic case, while in multi-child families it can sometimes be seen in more than two family members. With the advancement of genetic technology and its application in medicine, it has become possible to discover the cause of deafness using genetic diagnosis of deafness. Deafness genetic diagnosis has now been able to diagnose the exact causative gene for 60-80% of hereditary deafness and can identify the cause of many childhood deafnesses. The components of genetic diagnosis of hearing in children include prenatal diagnosis, newborn screening diagnosis, etiological diagnosis of neurological deafness, predictive testing, and carrier screening. For example, drug-related deafness is a common cause of hearing impairment in children, and China is a country with a high prevalence of drug-related deafness, with a large number of new drug-induced deafness patients each year. Aminoglycoside antibiotics such as streptomycin, gentamicin, kanamycin, and minomycin are the most common causes of drug-related deafness. Since there is no effective treatment for drug-induced deafness, prevention is especially important. With the increasing popularity of knowledge about drug-related deafness, a parent has been alert to the traditional aminoglycoside antibiotics such as gentamicin and streptomycin, but the clinical names of some new aminoglycosides using trade names, such as Aida, Sainan, Ximethan (etimesine sulfate), Logi, Knight (etimesine), Iksa (isopamycin sulfate), Pediatric Lipo (gentamicin sulfate), etc., have certain The names are confusing and may cause misuse by clinicians. Studies have shown that individuals carrying the mitochondrial gene A1555G mutation (the most frequent mutation) are highly sensitive to aminoglycoside antibiotics such as gentamicin and streptomycin, which is the reason for the so-called “one shot causes deafness”. Then we can perform genetic screening before using ototoxic drugs, find sensitive individuals, and avoid aminoglycoside antibiotics such as gentamicin forever to keep children away from drug-related deafness. There is also a specific inner ear malformation – the large vestibular aqueduct syndrome – that is also genetically related. The large vestibular aqueduct syndrome is a developmental malformation of the inner ear in which the tube connecting the vestibule to the cranial cavity becomes abnormally enlarged, like a triangular defect in the solid dam that separates a miniature pond from a giant reservoir. destroying the inner ear structure and causing hearing loss. This is how mild head trauma can lead to hearing loss in patients with large vestibular aqueduct. Many parents believe that they have never seen a similar case in their own or their family and that the disease is an external cause of inner ear dysplasia, but in fact it is an autosomal recessive disease, and both parents must be carriers of the PDS gene mutation for one quarter of their children to have the disease. Therefore, in single-child families, the disease is often seen as an epidemic, while in large families, more than two family members can sometimes be seen with the disease. Modern genetic diagnosis techniques can detect the PDS gene mutation in about 95% of Chinese patients with large vestibular plumbing. Genetic diagnosis of deafness has brought light to break through the voicelessness barrier. The genetic diagnosis can help to remove the psychological fear of deafness, guide the medication and daily behavior of the child and parents, and allow for a confident re-birth through prenatal diagnosis. If the child’s genetic diagnosis indicates that the congenital deafness is due to a mutation in the GJB2 gene, then the child’s ear nerve conduction pathways and auditory speech centers should be normal, and a cochlear implant can be performed with good results. Prenatal genetic diagnosis is especially significant for couples at risk of having a child with deafness. When they have a deaf child and are eager to know the status of their second child, genetic diagnosis coupled with prenatal diagnosis can clarify the genetic status of the fetus after 10 weeks of pregnancy and allow for early intervention to prevent the birth of a deaf child. Genetic diagnosis of deafness requires only a small amount of blood from the child’s vein. Compared to hearing tests and imaging tests such as X-rays, CT and MRI, genetic diagnosis of deafness is more targeted and specific, and it is easy to obtain materials and has a wide range of applications. Since “everything is decided by genes”, when the genetic diagnosis of deafness is clear, the patient basically gets a final diagnosis. The application of deafness genetic diagnosis to clinical diagnosis will have great economic and social benefits.