In China, 80% of deaf children with hearing and language disabilities are born to normal parents. There are also some children who are deaf because of “being slapped” or “being injected”, and can no longer listen to the voice of the world. Although hearing loss is irreversible, it can be prevented in advance.
Heredity can also cause deafness
Data show that about 466 million people worldwide suffer from disabled hearing loss, of which 34million are children. 60% of children’s hearing loss comes from preventable causes. China’s hearing and language disability ranks first among the five major disabilities, including visual disability, limb disability and intellectual disability, with 20.57 million people, accounting for 1.67% of China’s total population.
Deafness is not only caused by acquired accidents or bad ear habits, but also by ototoxic drugs, genetics, infections and diseases. Congenital hearing loss has become one of the most common birth defects in China. There are 1-3 congenital deafness in every 1000 newborns in China. Genetic factors account for more than 50% of childhood deafness factors. For example, if parents with normal hearing give birth to a baby with hearing impairment, it may be because both parents carry the same invisible gene and pass on the same invisible gene to the baby.
In China, genetic deafness in most people is caused by four gene mutations:
| Gene | Type of deafness | Clinical manifestation | Carrying rate of normal population | Carrying rate of deaf people |
| GJB2 | Congenital sensorineural deafness | Newborns show hearing impairment after birth, which is usually moderate to severe sensorineural deafness. Early diagnosis can avoid deafness caused by deafness. | 2-3% | 21% |
| SLC26A4 | Acquired delayed deafness | Newborns have normal hearing after birth. Once there are external factors such as head impact, cold and fever, it is easy to induce hearing loss to total deafness. Early diagnosis and early intervention can prevent “deafness with a slap” | 2% | 14% |
| 12S rRNA | Drug induced deafness | Newborns have normal hearing after birth. Once amino sugar is used, newborns have normal hearing after birth. Once amino sugar is used, it can prevent “one shot deafness” | 0.30% | 4.40% |
| GJB3 | Acquired high-frequency sensorineural deafness | Newborns have normal hearing after birth. When they develop to young adults, their hearing declines until severe deafness occurs. Early diagnosis and prognosis can be judged. | —— | —— |
By detecting these gene mutations, we can timely find patients with congenital hereditary deafness and individuals with delayed genetic and early drug-induced deafness, and improve the detection rate of individuals with hereditary deafness. According to the who survey, 50% of patients with hearing loss can avoid deafness through primary prevention, early diagnosis and treatment.
Experts suggest that the following groups should be screened for deafness genes:
- Both men and women or either of them are deaf during pregnancy;
- Both men and women or either of them during pregnancy are high-risk groups of deafness (such as hereditary deafness in the family);
- It is suggested that all pregnant women should be screened for deafness genes during pregnancy;
- Fetuses with high risk factors of hereditary deafness;
- Newborns.