Hereditary deafness, as the name implies, is a hearing impairment caused by a problem with the genetic material that controls the function of the auditory system. This problem not only affects the patient himself or herself, but can also be passed on to future generations, as if it were a recessive killer passed on from generation to generation in the human population. So, what is heredity? Heredity is like the saying “you reap what you sow”, which means that everything in nature follows a certain pattern to reproduce. Genetic inheritance is a phenomenon in which a species produces only offspring of the same species, and these offspring inherit the basic characteristics of the previous generation. In children with hereditary deafness, the root cause of the disease originates from a parent with a genetic defect, and it is the genes of the parent that are passed on to the affected child, causing the onset of the disease, while the parent’s hearing can be normal or abnormal. Why can seemingly normal parents conceive a genetically defective deaf child? Why is it that some deafness is passed on to males but not females? Why is it that some deafness is a lifelong regret caused by an accidental dose of medication? Why do some children lose their hearing dramatically after a fall? All of these reasons can be explained by the fact that deafness is hereditary. So, how do you think about hereditary deafness? In fact, about 60% of deafness is hereditary, caused by genetic factors, and mutations in genes associated with deafness are not uncommon in the normal population, which is one of the major reasons why the incidence of deafness remains high. Hereditary deafness can be autosomal dominant, that is, deafness occurs in about 50% of every generation in the family and can develop in both sexes. This form of inherited deafness often does not manifest itself at birth and gradually worsens into adolescence or middle age with hearing loss. This type of deafness can easily be attributed to environmental factors or thought to be caused by chance, ignoring the role of heredity in the process. Therefore, the possibility of hereditary deafness should be considered when more than two people in the family are found to have unknowingly started to develop hearing loss. Hereditary deafness can also occur in an autosomal recessive manner, and this type of inherited deafness is very common, with a rate of 70-80%. Deafness that is recessively inherited is often found to be severe or profoundly deaf at birth. What is often puzzling is that those parents with normal hearing give birth to a child with a congenital hearing impairment, and it is difficult for the parents to think that their child’s deafness is due to the fact that they are carriers of the deafness gene. It seems that recessive genetic deafness is not easily identified or in other words parents are reluctant to admit that their child is recessive genetically deaf. However, if there is a deaf child in the family, there is a 60% chance that the genetic cause is first considered, and in 70-80% of hereditary deafness is considered recessive, and among these recessive genes, the most common ones are the GJB2 mutation and the SLC26A4 mutation. Therefore, there is strong scientific evidence that genetic diagnosis can be used to determine the cause and mode of inheritance. In addition to autosomal dominant and recessive inheritance, there is also X-linked inheritance of hereditary deafness, mostly X-linked recessive inheritance, which is characterized by female carrier and male onset, which is said to be transmitted to male but not female. Although this type of deafness is uncommon, once diagnosed, it can effectively prevent the birth of deaf children. Therefore, when deafness occurs in a family with only male children, it is important to think that there is a genetic factor at play. Then, there is another very important type of drug deafness that can be said to be caused by the interaction of genetics and the environment. In this type of deafness, there is a mitochondrial gene mutation that is passed down the maternal line, so it is extremely sensitive to aminoglycosides and can lead to deafness with just one injection. Therefore, it is important to pay extra attention. If you find that someone in your family is deaf after having used aminoglycosides for a cold or fever, you should go to the hospital as soon as possible for genetic testing to see if there is a drug-sensitive gene mutation so that you can use drugs carefully in your future life to avoid tragedies. One type of deafness of great concern among so many is a genetic deafness associated with running and jumping, falls and mild head trauma – the name is called large vestibular aqueduct syndrome. These patients are not born with significant hearing loss, but they experience hearing loss after every fall, even after running and jumping movements, or after mild head trauma. In children under 3 years of age, it is difficult for parents to detect this, only to find that the child is dull to sounds and increasingly reluctant to respond quickly to parental commands, but still does not realize that the child has a hearing problem. Therefore, for a newborn, we need to screen each child’s hearing, and as the child grows, it is necessary to have a hearing test every year until the age of 6. This will prevent the child’s subsequent hearing loss from affecting the development of speech and leading to speech disorders, so that the child can grow up healthy and active. It is very difficult for parents to detect the disease, but once parents notice a decrease in their child’s hearing, they should go to the hospital for a detailed examination and a correct diagnosis. Vestibular aqueduct syndrome is also recessively inherited, so parents need genetic counseling from their doctor to get more information.